scsi: qla2xxx: Fix missed DMA unmap for NVMe ls requests

At NVMe ELS request time, request structure is DMA mapped and never
unmapped. Fix this by calling the unmap on ELS completion.

Link: https://lore.kernel.org/r/20220310092604.22950-5-njavali@marvell.com
Fixes: e84067d7

 ("scsi: qla2xxx: Add FC-NVMe F/W initialization and transport registration")
Cc: stable@vger.kernel.org
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>