perf tools: Move path related functions to util/path.h

Disentangling util.h header mess a bit more.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.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-aj6je8ly377i4upedmjzdsq6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/path.h

@@ -0,0 +1,9 @@
+#ifndef _PERF_PATH_H
+#define _PERF_PATH_H
+
+int path__join(char *bf, size_t size, const char *path1, const char *path2);
+int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3);
+
+bool is_regular_file(const char *file);
+
+#endif /* _PERF_PATH_H */