[POWERPC] pasemi: Fix thinko in dma_direct_ops setup

The first patch will just fall through and still set dma_data to a bad
value, make it return directly instead.
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>