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/util/namespaces.c

@@ -5,7 +5,6 @@
  */
 
 #include "namespaces.h"
-#include "util.h"
 #include "event.h"
 #include "get_current_dir_name.h"
 #include <sys/types.h>
@@ -18,6 +17,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <asm/bug.h>
+#include <linux/zalloc.h>
 
 struct namespaces *namespaces__new(struct namespaces_event *event)
 {