perf debug: Remove needless include directives from debug.h

All we need there is a forward declaration for 'union perf_event', so
remove it from there and add missing header directives in places using
things from this indirect include.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-7ftk0ztstqub1tirjj8o8xbl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/ui/browsers/scripts.c

@@ -9,6 +9,7 @@
 #include "../browser.h"
 #include "../libslang.h"
 #include "config.h"
+#include <linux/string.h>
 #include <linux/zalloc.h>
 
 #define SCRIPT_NAMELEN	128

tools/perf/ui/gtk/helpline.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <stdio.h>
 #include <string.h>
+#include <linux/kernel.h>
 
 #include "gtk.h"
 #include "../ui.h"

tools/perf/ui/gtk/util.c

@@ -3,6 +3,7 @@
 #include "../../util/debug.h"
 #include "gtk.h"
 
+#include <stdlib.h>
 #include <string.h>
 #include <linux/zalloc.h>
 

tools/perf/ui/tui/helpline.c

@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <pthread.h>
+#include <linux/kernel.h>
 
 #include "../../util/debug.h"
 #include "../helpline.h"

tools/perf/ui/util.c

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 #include "util.h"
 #include "../util/debug.h"
-
+#include <stdio.h>
 
 /*
  * Default error logging functions