[binutils-gdb] Remove some cleanups from location.c

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 4b217cc72b7ab04e2bea519f9fbd47d8952e08f5 ***

Author: Tom Tromey <tom@tromey.com>
Branch: master
Commit: 4b217cc72b7ab04e2bea519f9fbd47d8952e08f5

Remove some cleanups from location.c

This removes some more cleanups from location.c by using
unique_xmalloc_ptr.

gdb/ChangeLog
2017-04-12  Tom Tromey  <tom@tromey.com>

	* location.c (explicit_location_lex_one): Return a
	unique_xmalloc_ptr.
	(string_to_explicit_location): Update.  Remove cleanups.