ImageMagick 7.0.8-40 has a memory leak in Huffman2DEncodeImage in coders/ps2.c.
### Prerequisites

- [x] I have written a descriptive issue title
- [x] I have verified that I am using the latest version of ImageMagick
- [x] I have searched [open](https://github.com/ImageMagick/ImageMagick/issues) and [closed](https://github.com/ImageMagick/ImageMagick/issues?q=is%3Aissue+is%3Aclosed) issues to ensure it has not already been reported

### Description
```
==85960==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 13024 byte(s) in 1 object(s) allocated from:
    #0 0x7ffff6f02602 in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98602)
    #1 0x43f1f0 in AcquireMagickMemory MagickCore/memory.c:478
    #2 0x412eef in AcquireCriticalMemory MagickCore/memory-private.h:64
    #3 0x4153a9 in AcquireImageInfo MagickCore/image.c:349
    #4 0x418321 in CloneImageInfo MagickCore/image.c:944
    #5 0x64faad in Huffman2DEncodeImage coders/ps2.c:207
    #6 0x652046 in WritePS2Image coders/ps2.c:766
    #7 0x809316 in WriteImage MagickCore/constitute.c:1159
    #8 0x80a03b in WriteImages MagickCore/constitute.c:1376
    #9 0xb1573d in CompositeImageCommand MagickWand/composite.c:1676
    #10 0xc9d45d in MagickCommandGenesis MagickWand/mogrify.c:184
    #11 0x40e9e1 in MagickMain utilities/magick.c:149
    #12 0x40ebc2 in main utilities/magick.c:180
    #13 0x7ffff31f282f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)

SUMMARY: AddressSanitizer: 13024 byte(s) leaked in 1 allocation(s).
```
### Steps to Reproduce
/usr/local/bin/magick composite Memory-Leak-input1 Memory-Leak-input2 output.ps2

### System Configuration
<!-- Tell us about the environment where you are experiencing the bug -->

- ImageMagick version:
 '7.0.8-40'
- Environment (Operating system, version and so on):
Linux ubuntu 4.15.0-42-generic #45~16.04.1-Ubuntu SMP Mon Nov 19 13:02:27 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
- Additional information:
 ' ./configure CC="gcc" CXX="g++" CFLAGS="-g -fsanitize=address" -disable-shared'

<!-- Thanks for reporting the issue to ImageMagick! -->
testcase:
[ https://github.com/butterflyhack/pocs/blob/master/memory-leak-1.zip](https://github.com/butterflyhack/pocs/blob/master/memory-leak-1.zip) 

credit: ADlab of venustech
memory leak in Huffman2DEncodeImage
This is a GitHub Issue
repo:ImageMagick
owner:ImageMagick
Title : memory leak in Huffman2DEncodeImage
Issue date:

--- start body ---
### Prerequisites

- [x] I have written a descriptive issue title
- [x] I have verified that I am using the latest version of ImageMagick
- [x] I have searched [open](https://github.com/ImageMagick/ImageMagick/issues) and [closed](https://github.com/ImageMagick/ImageMagick/issues?q=is%3Aissue+is%3Aclosed) issues to ensure it has not already been reported

### Description
```
==85960==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 13024 byte(s) in 1 object(s) allocated from:
    #0 0x7ffff6f02602 in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98602)
    #1 0x43f1f0 in AcquireMagickMemory MagickCore/memory.c:478
    #2 0x412eef in AcquireCriticalMemory MagickCore/memory-private.h:64
    #3 0x4153a9 in AcquireImageInfo MagickCore/image.c:349
    #4 0x418321 in CloneImageInfo MagickCore/image.c:944
    #5 0x64faad in Huffman2DEncodeImage coders/ps2.c:207
    #6 0x652046 in WritePS2Image coders/ps2.c:766
    #7 0x809316 in WriteImage MagickCore/constitute.c:1159
    #8 0x80a03b in WriteImages MagickCore/constitute.c:1376
    #9 0xb1573d in CompositeImageCommand MagickWand/composite.c:1676
    #10 0xc9d45d in MagickCommandGenesis MagickWand/mogrify.c:184
    #11 0x40e9e1 in MagickMain utilities/magick.c:149
    #12 0x40ebc2 in main utilities/magick.c:180
    #13 0x7ffff31f282f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)

SUMMARY: AddressSanitizer: 13024 byte(s) leaked in 1 allocation(s).
```
### Steps to Reproduce
/usr/local/bin/magick composite Memory-Leak-input1 Memory-Leak-input2 output.ps2

### System Configuration
<!-- Tell us about the environment where you are experiencing the bug -->

- ImageMagick version:
 '7.0.8-40'
- Environment (Operating system, version and so on):
Linux ubuntu 4.15.0-42-generic #45~16.04.1-Ubuntu SMP Mon Nov 19 13:02:27 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
- Additional information:
 ' ./configure CC="gcc" CXX="g++" CFLAGS="-g -fsanitize=address" -disable-shared'

<!-- Thanks for reporting the issue to ImageMagick! -->
testcase:
[ https://github.com/butterflyhack/pocs/blob/master/memory-leak-1.zip](https://github.com/butterflyhack/pocs/blob/master/memory-leak-1.zip) 

credit: ADlab of venustech
--- end body ---
