[SCSI] NCR_D700: fix IRQ handler return type

drivers/scsi/NCR_D700.c: In function `NCR_D700_probe':
drivers/scsi/NCR_D700.c:322: warning: passing argument 2 of `request_irq' from incompatible pointer type
drivers/scsi/NCR_D700.c:322: warning: passing argument 2 of `request_irq' from incompatible pointer type
drivers/scsi/NCR_D700.c:322: warning: passing argument 2 of `request_irq' from incompatible pointer type

Signed-off-by: Zhenwen Xu <helight.xu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>