perf tools: Remove unused perf_pathdup, xstrdup functions

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-s87zi5d03m6rz622y1z6rlsa@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/util.h

@@ -162,7 +162,6 @@ static inline char *gitstrchrnul(const char *s, int c)
 /*
  * Wrappers:
  */
-char *xstrdup(const char *str);
 void *xrealloc(void *ptr, size_t size) __attribute__((weak));