Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/lib/zstd/huf_compress.c b/lib/zstd/huf_compress.c
index 40055a7..e727812 100644
--- a/lib/zstd/huf_compress.c
+++ b/lib/zstd/huf_compress.c
@@ -556,7 +556,9 @@
 	n = srcSize & ~3; /* join to mod 4 */
 	switch (srcSize & 3) {
 	case 3: HUF_encodeSymbol(&bitC, ip[n + 2], CTable); HUF_FLUSHBITS_2(&bitC);
+		/* fall through */
 	case 2: HUF_encodeSymbol(&bitC, ip[n + 1], CTable); HUF_FLUSHBITS_1(&bitC);
+		/* fall through */
 	case 1: HUF_encodeSymbol(&bitC, ip[n + 0], CTable); HUF_FLUSHBITS(&bitC);
 	case 0:
 	default:;