Fix a building issue

src/utils.c

@@ -233,7 +233,7 @@ void *
 ss_align(size_t size)
 {
     int err;
-    void *tmp;
+    void *tmp = NULL;
 #ifdef HAVE_POSIX_MEMALIGN
     err = posix_memalign(&tmp, sizeof(void *), size);
 #else