[binutils-gdb] Remove a cleanup in Python

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 0d50bde32b92821c9f1f660d273e6c996d26dc9f ***

Author: Tom Tromey <tom@tromey.com>
Branch: master
Commit: 0d50bde32b92821c9f1f660d273e6c996d26dc9f

Remove a cleanup in Python

This removes cleanups from gdbpy_decode_line, in favor of a use of
unique_xmalloc_ptr.

ChangeLog
2017-08-03  Tom Tromey  <tom@tromey.com>

	* python/python.c (gdbpy_decode_line): Use unique_xmalloc_ptr.