perf probe: Handle strdup() failure

We could end up returning 0 (Ok) with a NULL raw_path. Fix it.
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naohiro Aota <naota@elisp.net>
Link: http://lkml.kernel.org/n/tip-l0kcbcg5f4nnzqt01cv42vec@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/probe-event.c

@@ -533,7 +533,7 @@ static int get_real_path(const char *raw_path, const char *comp_dir,
 		else {
 			if (access(raw_path, R_OK) == 0) {
 				*new_path = strdup(raw_path);
-				return 0;
+				return *new_path ? 0 : -ENOMEM;
 			} else
 				return -errno;
 		}