Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/bpf/bpftool/perf.c b/tools/bpf/bpftool/perf.c
index b76b77d..b2046f3 100644
--- a/tools/bpf/bpftool/perf.c
+++ b/tools/bpf/bpftool/perf.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
 // Copyright (C) 2018 Facebook
 // Author: Yonghong Song <yhs@fb.com>
 
@@ -104,6 +104,8 @@
 		jsonw_string_field(json_wtr, "filename", buf);
 		jsonw_lluint_field(json_wtr, "offset", probe_offset);
 		break;
+	default:
+		break;
 	}
 	jsonw_end_object(json_wtr);
 }
@@ -140,6 +142,8 @@
 		printf("uretprobe  filename %s  offset %llu\n", buf,
 		       probe_offset);
 		break;
+	default:
+		break;
 	}
 }