branch: work in subdirectories.

Noticed by Andy Whitcroft

Signed-off-by: Junio C Hamano <junkio@cox.net>

git.c

@@ -222,7 +222,7 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
 		{ "annotate", cmd_annotate, },
 		{ "apply", cmd_apply },
 		{ "archive", cmd_archive },
-		{ "branch", cmd_branch },
+		{ "branch", cmd_branch, RUN_SETUP },
 		{ "cat-file", cmd_cat_file, RUN_SETUP },
 		{ "checkout-index", cmd_checkout_index, RUN_SETUP },
 		{ "check-ref-format", cmd_check_ref_format },