use declarations from builtin.h for builtin commands

Signed-off-by: NMatthias Kestenholz <matthias@spinlock.ch>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

builtin-fmt-merge-msg.c

+#include "builtin.h"
 #include "cache.h"
 #include "commit.h"
 #include "diff.h"
@@ -242,7 +243,7 @@ static void shortlog(const char *name, unsigned char *sha1,
 	free_list(&subjects);
 }
 
-int cmd_fmt_merge_msg(int argc, char **argv, const char *prefix)
+int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 {
 	int limit = 20, i = 0;
 	char line[1024];

builtin-prune-packed.c

+#include "builtin.h"
 #include "cache.h"
 
 static const char prune_packed_usage[] =
@@ -54,7 +55,7 @@ static void prune_packed_objects(void)
 	}
 }
 
-int cmd_prune_packed(int argc, char **argv, const char *prefix)
+int cmd_prune_packed(int argc, const char **argv, const char *prefix)
 {
 	int i;