Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/perf/builtin-help.c b/tools/perf/builtin-help.c
index 1c41b4e..3976aeb 100644
--- a/tools/perf/builtin-help.c
+++ b/tools/perf/builtin-help.c
@@ -4,8 +4,9 @@
  *
  * Builtin help command
  */
-#include "perf.h"
+#include "util/cache.h"
 #include "util/config.h"
+#include "util/strbuf.h"
 #include "builtin.h"
 #include <subcmd/exec-cmd.h>
 #include "common-cmds.h"
@@ -14,8 +15,12 @@
 #include <subcmd/help.h>
 #include "util/debug.h"
 #include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/zalloc.h>
 #include <errno.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
@@ -189,7 +194,7 @@
 	while (*p)
 		p = &((*p)->next);
 	*p = zalloc(sizeof(**p) + len + 1);
-	strncpy((*p)->name, name, len);
+	strcpy((*p)->name, name);
 }
 
 static int supported_man_viewer(const char *name, size_t len)