builtin/apply: remove misleading comment on lock_file field

Just like pointer field like prefix, the piece of memory pointed at
by lock_file field is not owned by the apply_state structure.  It is
true that the caller needs to be careful about the lifetime rule for
lockfile instances, but that is none of this API's business.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/apply.c

@@ -52,10 +52,7 @@ struct apply_state {
 	const char *prefix;
 	int prefix_length;
 
-	/*
+	/* These are lock_file related */
-	 * Since lockfile.c keeps a linked list of all created
-	 * lock_file structures, it isn't safe to free(lock_file).
-	 */
 	struct lock_file *lock_file;
 	int newfd;