scsi: qedf: Honor qed_ops->common->set_fp_int() return code.

We need to check the return code the set_fp_int() callback in case we were
not allocated any fastpath interrupts or there was an error setting up the
fastpath interrupts from the qed perspective.

Signed-off-by: Chad Dupuis <chad.dupuis@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>