remove unnecessary parameter from get_patch_ids()

get_patch_ids() takes an already initialized rev_info and a
prefix. The prefix is used when initalizing a second rev_info. Since
the initialized rev_info already has a prefix and the prefix never
changes, we can use the prefix from the initialized rev_info to
initialize the second rev_info.

Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/log.c

@@ -696,7 +696,7 @@ static int reopen_stdout(struct commit *commit, const char *subject,
 	return 0;
 }
 
-static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const char *prefix)
+static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids)
 {
 	struct rev_info check_rev;
 	struct commit *commit;
@@ -717,7 +717,7 @@ static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const cha
 	init_patch_ids(ids);
 
 	/* given a range a..b get all patch ids for b..a */
-	init_revisions(&check_rev, prefix);
+	init_revisions(&check_rev, rev->prefix);
 	o1->flags ^= UNINTERESTING;
 	o2->flags ^= UNINTERESTING;
 	add_pending_object(&check_rev, o1, "o1");
@@ -1306,7 +1306,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
 				return 0;
 		}
-		get_patch_ids(&rev, &ids, prefix);
+		get_patch_ids(&rev, &ids);
 	}
 
 	if (!use_stdout)
@@ -1525,7 +1525,7 @@ int cmd_cherry(int argc, const char **argv, const char *prefix)
 			return 0;
 	}
 
-	get_patch_ids(&revs, &ids, prefix);
+	get_patch_ids(&revs, &ids);
 
 	if (limit && add_pending_commit(limit, &revs, UNINTERESTING))
 		die(_("Unknown commit %s"), limit);