scsi: esp_scsi: Always clear msg_out_len after MESSAGE OUT phase

After sending a message, always clear esp->msg_out_len. Otherwise,
eh_abort_handler may subsequently fail to send an ABORT TASK SET
message.
Tested-by: NStan Johnson <userm57@yahoo.com>
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/esp_scsi.c

@@ -1951,6 +1951,8 @@ static int esp_process_event(struct esp *esp)
 				scsi_esp_cmd(esp, ESP_CMD_NULL);
 		}
 
+		esp->msg_out_len = 0;
+
 		esp_event(esp, ESP_EVENT_CHECK_PHASE);
 		goto again;
 	case ESP_EVENT_MSGIN: