scsi: bnx2fc: Process the RQE with CQE in interrupt context

Filesystem goes to read-only after continuous error injection because RQE
was handled in deferred context, leading to mismatch between CQE and RQE.

Specifically, this patch makes the following changes:

 - Process the RQE with CQE in interrupt context, before putting it into
   the work queue.

 - Producer and consumer indices are also updated in the interrupt context
   to guarantee the the order of processing.

[mkp: fixed bad indentation]

Link: https://lore.kernel.org/r/20200327054849.15947-2-skashyap@marvell.com


Signed-off-by: Javed Hasan <jhasan@marvell.com>
Signed-off-by: Saurav Kashyap <skashyap@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>