tools lib: Adopt zalloc()/zfree() from tools/perf

Eroding a bit more the tools/perf/util/util.h hodpodge header.

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-natazosyn9rwjka25tvcnyi0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-timechart.c

@@ -13,9 +13,6 @@
 #include <traceevent/event-parse.h>
 
 #include "builtin.h"
-
-#include "util/util.h"
-
 #include "util/color.h"
 #include <linux/list.h>
 #include "util/cache.h"
@@ -24,6 +21,7 @@
 #include <linux/kernel.h>
 #include <linux/rbtree.h>
 #include <linux/time64.h>
+#include <linux/zalloc.h>
 #include "util/symbol.h"
 #include "util/thread.h"
 #include "util/callchain.h"