refs: inline function do_not_prune()

Function do_not_prune() was redundantly checking REF_ISSYMREF, which
was already tested at the top of pack_one_ref(), so remove that check.
And the rest was trivial, so inline the function.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

refs.c

@@ -1996,14 +1996,6 @@ struct pack_refs_cb_data {
 	FILE *refs_file;
 };
 
-static int do_not_prune(int flags)
-{
-	/* If it is already packed or if it is a symref,
-	 * do not prune it.
-	 */
-	return (flags & (REF_ISSYMREF|REF_ISPACKED));
-}
-
 static int pack_one_ref(struct ref_entry *entry, void *cb_data)
 {
 	struct pack_refs_cb_data *cb = cb_data;
@@ -2031,7 +2023,8 @@ static int pack_one_ref(struct ref_entry *entry, void *cb_data)
 				sha1_to_hex(o->sha1));
 	}
 
-	if ((cb->flags & PACK_REFS_PRUNE) && !do_not_prune(entry->flag)) {
+	/* If the ref was already packed, there is no need to prune it. */
+	if ((cb->flags & PACK_REFS_PRUNE) && !(entry->flag & REF_ISPACKED)) {
 		int namelen = strlen(entry->name) + 1;
 		struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
 		hashcpy(n->sha1, entry->u.value.sha1);