provider/powerdns: Correct dangling resource check

This fix prevents tests incorrectly reporting dangling resources. It is
not sufficient to check just whether or not an error occurred when
iterating over the listed resources - checking the bool returned is also
required.

builtin/providers/powerdns/resource_powerdns_record_test.go

@@ -213,10 +213,14 @@ func testAccCheckPDNSRecordDestroy(s *terraform.State) error {
 		}
 
 		client := testAccProvider.Meta().(*Client)
-		_, err := client.RecordExistsByID(rs.Primary.Attributes["zone"], rs.Primary.ID)
-		if err == nil {
+		exists, err := client.RecordExistsByID(rs.Primary.Attributes["zone"], rs.Primary.ID)
+		if err != nil {
+			return fmt.Errorf("Error checking if record still exists: %#v", rs.Primary.ID)
+		}
+		if exists {
 			return fmt.Errorf("Record still exists: %#v", rs.Primary.ID)
 		}
+
 	}
 	return nil
 }