Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/lib/zstd/compress.c b/lib/zstd/compress.c
index f9166cf..5e0b670 100644
--- a/lib/zstd/compress.c
+++ b/lib/zstd/compress.c
@@ -3182,6 +3182,7 @@
 				zcs->outBuffFlushedSize = 0;
 				zcs->stage = zcss_flush; /* pass-through to flush stage */
 			}
+			/* fall through */
 
 		case zcss_flush: {
 			size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;