Change prettify_ref to prettify_refname

In preparation to be used when the ref object is not available

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin-fetch.c b/builtin-fetch.c
index 3c998ea..ebd0c08 100644
--- a/builtin-fetch.c
+++ b/builtin-fetch.c
@@ -197,7 +197,7 @@
 	struct commit *current = NULL, *updated;
 	enum object_type type;
 	struct branch *current_branch = branch_get(NULL);
-	const char *pretty_ref = prettify_ref(ref);
+	const char *pretty_ref = prettify_refname(ref->name);
 
 	*display = 0;
 	type = sha1_object_info(ref->new_sha1, NULL);