We need to restore all variables including error (as it is done in the
upstream kernel). The variable error was errorneously not restored when
backporting the patch ede4cebc
(prepend_path() needs to reinitialize dentry/vfsmount/mnt on restarts).

This should be applied only to the 3.12 series.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>