name-rev: cleanup name_ref()

name-rev: cleanup name_ref()

Earlier patches in this series moved a couple of conditions from the
recursive name_rev() function into its caller name_ref(), for no other
reason than to make eliminating the recursion a bit easier to follow.

Since the previous patch name_rev() is not recursive anymore, so let's
move all those conditions back into name_rev().

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>