scsi: lpfc: Correct soft lockup when running mds diagnostics

scsi: lpfc: Correct soft lockup when running mds diagnostics

[ Upstream commit 0ef01a2d95fd62bb4f536e7ce4d5e8e74b97a244 ]

When running an mds diagnostic that passes frames with the switch, soft
lockups are detected. The driver is in a CQE processing loop and has
sufficient amount of traffic that it never exits the ring processing routine,
thus the "lockup".

Cap the number of elements in the work processing routine to 64 elements. This
ensures that the cpu will be given up and the handler reschedule to process
additional items.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>