builtin: add a repository parameter for builtin functions

In order to reduce the usage of the global the_repository, add a
parameter to builtin functions that will get passed a repository
variable.

This commit uses UNUSED on most of the builtin functions, as subsequent
commits will modify the actual builtins to pass the repository parameter
down.

Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/mv.c

@@ -178,7 +178,10 @@ static void remove_empty_src_dirs(const char **src_dir, size_t src_dir_nr)
 	strbuf_release(&a_src_dir);
 }
 
-int cmd_mv(int argc, const char **argv, const char *prefix)
+int cmd_mv(int argc,
+	   const char **argv,
+	   const char *prefix,
+	   struct repository *repo UNUSED)
 {
 	int i, flags, gitmodules_modified = 0;
 	int verbose = 0, show_only = 0, force = 0, ignore_errors = 0, ignore_sparse = 0;