be2iscsi: Remove unused mcc_cq_lock

mcc_cq_lock spin_lock is used only in beiscsi_process_mcc which is
called only when all interrupts are disabled from mgmt_epfw_cleanup
during unloading of driver. There is no other context where there can be
contention for the processing of CQ.

Signed-off-by: Jitendra Bhivare <jitendra.bhivare@broadcom.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>