drivers/parport/parport_ip32.c: use PTR_ERR_OR_ZERO

replace IS_ERR/PTR_ERR

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>