scsi: mpi3mr: Reset the pending interrupt flag

scsi: mpi3mr: Reset the pending interrupt flag

If an admin interrupt is missed, admin_pend_isr may stay set and trigger
admin reply processing even when no admin I/Os are pending.

Clearing/Resetting it in the admin completion path prevents this.

Fixes: ca41929b2ed5 ("scsi: mpi3mr: Check admin reply queue from Watchdog")
Cc: stable@vger.kernel.org
Co-developed-by: Sathya Prakash <sathya.prakash@broadcom.com>
Signed-off-by: Sathya Prakash <sathya.prakash@broadcom.com>
Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Link: https://lore.kernel.org/r/20250411111419.135485-3-ranjan.kumar@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>