scan-skel.l: consider m4 notes as related to "complaint" errors

* src/scan-skel.l (flag): Here.

src/scan-skel.l

@@ -186,7 +186,7 @@ flag (const char *arg)
   else if (STREQ (arg, "fatal"))
     return fatal;
   else if (STREQ (arg, "note"))
-    return silent;
+    return silent | complaint;
   else if (STREQ (arg, "warn"))
     return Wother;
   else