Fix reading Series with read_hdf
 - [x] closes #16583
 - [x] tests added / passed
 - [x] passes ``git diff upstream/master --name-only -- '*.py' | flake8 --diff``
 - [x] whatsnew entry

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=h1) Report
> Merging [#16610](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/bf9997520443e0a5f505f11e11f46290ea95b3a3?src=pr&el=desc) will **not change** coverage.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/16610/graphs/tree.svg?token=eZ4WkYLtcO&src=pr&height=150&width=650)](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master   #16610   +/-   ##
=======================================
  Coverage   90.93%   90.93%           
=======================================
  Files         161      161           
  Lines       49267    49267           
=======================================
  Hits        44800    44800           
  Misses       4467     4467
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.69% <66.66%> (ø)` | :arrow_up: |
| #single | `40.23% <100%> (+0.01%)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/pytables.py](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=tree#diff-cGFuZGFzL2lvL3B5dGFibGVzLnB5) | `93.12% <100%> (ø)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=footer). Last update [bf99975...7921b8d](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=h1) Report
> Merging [#16610](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/125c414389320dc67ecaffddc65878c01822064e?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/16610/graphs/tree.svg?width=650&height=150&src=pr&token=eZ4WkYLtcO)](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #16610      +/-   ##
==========================================
- Coverage   90.93%   90.91%   -0.02%     
==========================================
  Files         161      161              
  Lines       49288    49284       -4     
==========================================
- Hits        44821    44809      -12     
- Misses       4467     4475       +8
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.69% <100%> (-0.02%)` | :arrow_down: |
| #single | `40.17% <100%> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/pytables.py](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=tree#diff-cGFuZGFzL2lvL3B5dGFibGVzLnB5) | `92.87% <100%> (ø)` | :arrow_up: |
| [pandas/plotting/\_core.py](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb3JlLnB5) | `81.83% <0%> (-0.7%)` | :arrow_down: |
| [pandas/core/strings.py](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc3RyaW5ncy5weQ==) | `98.48% <0%> (ø)` | :arrow_up: |
| [pandas/core/indexing.py](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhpbmcucHk=) | `94.01% <0%> (+0.08%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=footer). Last update [125c414...d41ea74](https://codecov.io/gh/pandas-dev/pandas/pull/16610?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 The Travis CI tests seem to be failing because of a MemoryError in PyArrow, I'm not sure what that could have to do with this change. @frexvahi thanks for the report. Yes something happened on Travis with this import. This PR lgtm. Will merge soon. thanks. thanks!