Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index 8c9d412..e7cf0a1 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -398,6 +398,7 @@
 		}
 		if (dstat == 0x08)
 			break;
+		/* else, fall through */
 	case 0x04:
 		/* Device end interrupt. */
 		if ((raw = req->info) == NULL)