misc: fix sonarclound warnings

Type: fix
Ticket: VPP-1888
Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: I9c2fb926a5e010658088a74051c8c3462ff61734

src/plugins/dns/dns_test.c

@@ -123,6 +123,12 @@ api_dns_resolve_name (vat_main_t * vam)
 	break;
     }
 
+  if (name == 0)
+    {
+      errmsg ("missing name to resolve");
+      return -99;
+    }
+
   if (vec_len (name) > 127)
     {
       errmsg ("name too long");