scsi: mpi3mr: Delete unnecessary NULL check

The "mrioc->intr_info" pointer can't be NULL, but if it could then the
second iteration through the loop would Oops.  Let's delete the confusing
and impossible NULL check.

Link: https://lore.kernel.org/r/YMCJKgykDYtyvY44@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>