pack-objects: swap 'show_{object,commit}_pack_hint'

show_commit_pack_hint() has heretofore been a noop, so its position
within its compilation unit only needs to appear before its first use.

But the following commit will sometimes have `show_commit_pack_hint()`
call `show_object_pack_hint()`, so reorder the former to appear after
the latter to minimize the code movement in that patch.

Suggested-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: ttaylorr

builtin/pack-objects.c

@@ -3748,12 +3748,6 @@ static int add_object_entry_from_pack(const struct object_id *oid,
 	return 0;
 }
 
-static void show_commit_pack_hint(struct commit *commit UNUSED,
-				  void *data UNUSED)
-{
-	/* nothing to do; commits don't have a namehash */
-}
-
 static void show_object_pack_hint(struct object *object, const char *name,
 				  void *data UNUSED)
 {
@@ -3776,6 +3770,12 @@ static void show_object_pack_hint(struct object *object, const char *name,
 	stdin_packs_hints_nr++;
 }
 
+static void show_commit_pack_hint(struct commit *commit UNUSED,
+				  void *data UNUSED)
+{
+	/* nothing to do; commits don't have a namehash */
+}
+
 static int pack_mtime_cmp(const void *_a, const void *_b)
 {
 	struct packed_git *a = ((const struct string_list_item*)_a)->util;