Remove make_cleanup_defer_target_commit_resume

Remove make_cleanup_defer_target_commit_resume

This removes make_cleanup_defer_target_commit_resume in favor of using
scoped_restore.

gdb/ChangeLog
2017-09-29  Tom Tromey  <tom@tromey.com>

	* target.h (make_scoped_defer_target_commit_resume): Update.
	* target.c (make_scoped_defer_target_commit_resume): Rename from
	make_cleanup_defer_target_commit_resume.  Return a
	scoped_restore.
	* infrun.c (proceed): Use make_scoped_defer_target_commit_resume.