scsi: fnic: Use mempool for receive frames

scsi: fnic: Use mempool for receive frames

The receive frames are constantly replenished so we should rather use a
mempool here.

fip_frame_queue is an rxq. Deallocate it in fnic_free_rxq().

Tested-by: Karan Tilak Kumar <kartilak@cisco.com>
Reviewed-by: Sesidhar Baddela <sebaddel@cisco.com>
Reviewed-by: Arulprabhu Ponnusamy <arulponn@cisco.com>
Reviewed-by: Gian Carlo Boffa <gcboffa@cisco.com>
Reviewed-by: Arun Easi <aeasi@cisco.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Karan Tilak Kumar <kartilak@cisco.com>
Co-developed-by: Hannes Reinecke <hare@kernel.org>
Link: https://patch.msgid.link/20260217223943.7938-1-kartilak@cisco.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>