Use a common function to get the pretty name of refs

The result should be consistent between fetch and push, so we ought to
use the same code in both cases, even though it's short.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refs.h

@@ -79,6 +79,8 @@ extern int for_each_reflog(each_ref_fn, void *);
 #define CHECK_REF_FORMAT_WILDCARD (-3)
 extern int check_ref_format(const char *target);
 
+extern const char *prettify_ref(const struct ref *ref);
+
 /** rename ref, return 0 on success **/
 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);