add logref support to git-symbolic-ref

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/builtin-branch.c b/builtin-branch.c
index d60690b..76f174f 100644
--- a/builtin-branch.c
+++ b/builtin-branch.c
@@ -381,7 +381,8 @@
 	if (rename_ref(oldref, newref, logmsg))
 		die("Branch rename failed");
 
-	if (!strcmp(oldname, head) && create_symref("HEAD", newref))
+	/* no need to pass logmsg here as HEAD didn't really move */
+	if (!strcmp(oldname, head) && create_symref("HEAD", newref, NULL))
 		die("Branch renamed to %s, but HEAD is not updated!", newname);
 }