perf tests: Show python test script in verbose mode

To help figure out where it is getting the binding.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/python-use.c

@@ -18,6 +18,7 @@ int test__python_use(struct test *test __maybe_unused, int subtest __maybe_unuse
 		     PYTHONPATH, PYTHON, verbose > 0 ? "" : "2> /dev/null") < 0)
 		return -1;
 
+	pr_debug("python usage test: \"%s\"\n", cmd);
 	ret = system(cmd) ? -1 : 0;
 	free(cmd);
 	return ret;