perf tools: Fixup get_current_dir_name() compilation

strdup() prototype doesn't live in stdlib.h .

Add limits.h for PATH_MAX definition as well.

This fixes the build on Android.
Signed-off-by: NAlexey Dobriyan (SK hynix) <adobriyan@gmail.com>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/YRukaQbrgDWhiwGr@localhost.localdomainSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/get_current_dir_name.c

@@ -3,8 +3,9 @@
 //
 #ifndef HAVE_GET_CURRENT_DIR_NAME
 #include "get_current_dir_name.h"
+#include <limits.h>
+#include <string.h>
 #include <unistd.h>
-#include <stdlib.h>
 
 /* Android's 'bionic' library, for one, doesn't have this */