patch 8.2.2209: Vim9: return type of => lambda not parsed

Problem:    Vim9: return type of => lambda not parsed.
Solution:   Parse and use the return type.
diff --git a/src/eval.c b/src/eval.c
index e612070..e3a3592 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -868,7 +868,9 @@
 		char_u	 *tp = skipwhite(p + 1);
 
 		// parse the type after the name
-		lp->ll_type = parse_type(&tp, &si->sn_type_list);
+		lp->ll_type = parse_type(&tp, &si->sn_type_list, !quiet);
+		if (lp->ll_type == NULL && !quiet)
+		    return NULL;
 		lp->ll_name_end = tp;
 	    }
 	}