perf header: Fix memory leak for the "Not caching a kptr_restrict'ed /proc/kallsyms" case

cppcheck reported:
[util/header.c:316]: (error) Memory leak: filename
[util/header.c:316]: (error) Memory leak: linkname
Signed-off-by: NThomas Jarosch <thomas.jarosch@intra2net.com>
Link: http://lkml.kernel.org/r/9377388.0eFDp53iW6@stormSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/header.c

@@ -313,7 +313,8 @@ int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 	if (is_kallsyms) {
 		if (symbol_conf.kptr_restrict) {
 			pr_debug("Not caching a kptr_restrict'ed /proc/kallsyms\n");
-			return 0;
+			err = 0;
+			goto out_free;
 		}
 		realname = (char *) name;
 	} else