Fix missing not in format._put_lines
## [Current coverage](https://codecov.io/gh/pydata/pandas/pull/13552?src=pr) is 84.31% (diff: 100%)

> Merging [#13552](https://codecov.io/gh/pydata/pandas/pull/13552?src=pr) into [master](https://codecov.io/gh/pydata/pandas/branch/master?src=pr) will decrease coverage by **0.97%**

``` diff
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  Lines         50241      51157   +916   
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+ Hits          42851      43131   +280   
- Misses         7390       8026   +636   
  Partials          0          0          
```

> Powered by [Codecov](https://codecov.io?src=pr). Last update [5d791cc...d599b10](https://codecov.io/gh/pydata/pandas/compare/5d791cc7d955c0b074ad602eb03fa32bd3e17503...d599b10667fd83a5e865059123da56bc715da306?src=pr)
 @jreback the following raises a TypeError

``` python
import pandas as pd
from io import StringIO
buf = StringIO()
pd.DataFrame().info(buf=buf)

   2642     if any(isinstance(x, compat.text_type) for x in lines):
   2643         lines = [compat.text_type(x) for x in lines]
-> 2644     buf.write('\n'.join(lines))
   2645 
   2646 

TypeError: unicode argument expected, got 'str'
```

 Which I believe this PR fixes (and is the proper intention of the code)
 @limx0 Can you add a test for the actual `info` issue?
 @jorisvandenbossche this is now working in the latest master. Closing this PR
