W1 core prints "Failed to register master driver" if error happens
on registering SLAVE driver. Fix it.
Signed-off-by: NDmitry Artamonow <mad_soft@inbox.ru>
Acked-by: NEvgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>