Supress a coverity false positive

The variable substrs is not allocated if want_substrs is false.

Author: jan-cerny

src/OVAL/probes/independent/textfilecontent54.c

@@ -354,6 +354,7 @@ static int process_file(const char *prefix, const char *path, const char *file,
 		free(whole_path);
 	free(whole_path_with_prefix);
 
+	/* coverity[leaked_storage] - substrs is not leaked */
 	return ret;
 }