checkout_paths(): remove unneeded flag variable

It is never read, so we can pass NULL to resolve_ref_unsafe().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/checkout.c

@@ -242,7 +242,6 @@ static int checkout_paths(const struct checkout_opts *opts,
 	struct checkout state;
 	static char *ps_matched;
 	unsigned char rev[20];
-	int flag;
 	struct commit *head;
 	int errs = 0;
 	struct lock_file *lock_file;
@@ -375,7 +374,7 @@ static int checkout_paths(const struct checkout_opts *opts,
 	if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
 		die(_("unable to write new index file"));
 
-	read_ref_full("HEAD", 0, rev, &flag);
+	read_ref_full("HEAD", 0, rev, NULL);
 	head = lookup_commit_reference_gently(rev, 1);
 
 	errs |= post_checkout_hook(head, head, 0);