scsi: sun3x_esp: Add IRQ check

scsi: sun3x_esp: Add IRQ check

The driver neglects to check the result of platform_get_irq()'s call and
blithely passes the negative error codes to request_irq() (which takes
*unsigned* IRQ #), causing it to fail with -EINVAL, overriding the real
error code.  Stop calling request_irq() with the invalid IRQ #s.

Link: https://lore.kernel.org/r/363eb4c8-a3bf-4dc9-2a9e-90f349030a15@omprussia.ru
Fixes: 0bb67f181834 ("[SCSI] sun3x_esp: convert to esp_scsi")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>