spi: fix error paths on txx9spi_probe

Some error paths in txx9spi_probe wrongly return 0.  This patch fixes them by
using the devres interfaces.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>