ypr0: Get it up and running again

7d1a47cf13 introduced a regression that broke it completely so that
it couldn't boot into the main menu anymore. It had a faulty call to
get_volume_name() which made handle_special_links() act up. This broke
every open() and opendir() (and friends) library calls.

Change-Id: I399960ca8fb6e3bcc1f25c9b4a3c19a6d28b77bd