Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/samples/bpf/sockex3_user.c b/samples/bpf/sockex3_user.c
index 5ba3ae9..bbb1cd0 100644
--- a/samples/bpf/sockex3_user.c
+++ b/samples/bpf/sockex3_user.c
@@ -13,7 +13,7 @@
 #define PARSE_IP_PROG_FD (prog_fd[0])
 #define PROG_ARRAY_FD (map_fd[0])
 
-struct bpf_flow_keys {
+struct flow_key_record {
 	__be32 src;
 	__be32 dst;
 	union {
@@ -58,13 +58,13 @@
 			  sizeof(__u32)) == 0);
 
 	if (argc > 1)
-		f = popen("ping -c5 localhost", "r");
+		f = popen("ping -4 -c5 localhost", "r");
 	else
 		f = popen("netperf -l 4 localhost", "r");
 	(void) f;
 
 	for (i = 0; i < 5; i++) {
-		struct bpf_flow_keys key = {}, next_key;
+		struct flow_key_record key = {}, next_key;
 		struct pair value;
 
 		sleep(1);