scsi: qla4xxx: Document qla4xxx_process_ddb()'s 'conn_err'

Fixes the following W=1 kernel build warning(s):

 drivers/scsi/qla4xxx/ql4_init.c:1170: warning: Function parameter or member 'conn_err' not described in 'qla4xxx_process_ddb_changed'

Link: https://lore.kernel.org/r/20200721164148.2617584-30-lee.jones@linaro.org
Cc: QLogic-Storage-Upstream@qlogic.com
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla4xxx/ql4_init.c

@@ -1161,6 +1161,7 @@ int qla4xxx_flash_ddb_change(struct scsi_qla_host *ha, uint32_t fw_ddb_index,
  * @ha: Pointer to host adapter structure.
  * @fw_ddb_index: Firmware's device database index
  * @state: Device state
+ * @conn_err: Unused
  *
  * This routine processes a Decive Database Changed AEN Event.
  **/