scsi: qla2xxx: Fix WARN_ON in qla_nvme_register_hba

qla_nvme_register_hba() puts out a warning when there are not enough queue
pairs available for FC-NVME.  Just fail the NVME registration rather than a
WARNING + call Trace.

Link: https://lore.kernel.org/r/20200806111014.28434-8-njavali@marvell.com
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>

Author: Arun Easi

drivers/scsi/qla2xxx/qla_def.h

@@ -3880,6 +3880,7 @@ struct qla_hw_data {
 		uint32_t	scm_supported_f:1;
 				/* Enabled in Driver */
 		uint32_t	scm_enabled:1;
+		uint32_t	max_req_queue_warned:1;
 	} flags;
 
 	uint16_t max_exchg;

drivers/scsi/qla2xxx/qla_nvme.c

@@ -687,7 +687,15 @@ int qla_nvme_register_hba(struct scsi_qla_host *vha)
 	tmpl = &qla_nvme_fc_transport;
 
 	WARN_ON(vha->nvme_local_port);
-	WARN_ON(ha->max_req_queues < 3);
+
+	if (ha->max_req_queues < 3) {
+		if (!ha->flags.max_req_queue_warned)
+			ql_log(ql_log_info, vha, 0x2120,
+			       "%s: Disabling FC-NVME due to lack of free queue pairs (%d).\n",
+			       __func__, ha->max_req_queues);
+		ha->flags.max_req_queue_warned = 1;
+		return ret;
+	}
 
 	qla_nvme_fc_transport.max_hw_queues =
 	    min((uint8_t)(qla_nvme_fc_transport.max_hw_queues),