scsi: lpfc: Fix I/O block after enabling managed congestion mode

If the congestion management framework dynamically enables, it may do so
while I/O is in flight. The updates of cmf info due to inflight I/O
completing may happen before values have been initialized.

Fix by ensure cmf_max_bytes_per_interval is initialized when checking
bandwidth utilization for SCSI layer blocking.

Link: https://lore.kernel.org/r/20210910233159.115896-12-jsmart2021@gmail.com
Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_scsi.c

@@ -3961,7 +3961,8 @@ lpfc_update_cmf_cmd(struct lpfc_hba *phba, uint32_t size)
 	int cpu;
 
 	/* At this point we are either LPFC_CFG_MANAGED or LPFC_CFG_MONITOR */
-	if (phba->cmf_active_mode == LPFC_CFG_MANAGED) {
+	if (phba->cmf_active_mode == LPFC_CFG_MANAGED &&
+	    phba->cmf_max_bytes_per_interval) {
 		total = 0;
 		for_each_present_cpu(cpu) {
 			cgs = per_cpu_ptr(phba->cmf_stat, cpu);