remove unnecessary if

Author: sarven

lib/Doctrine/DBAL/Driver/PDOSqlsrv/PDOSqlsrvStatement.php

@@ -143,11 +143,7 @@ public function execute($params = null)
                 }
             }
         }
-
-        if (! $this->stmt) {
-            $this->stmt = $this->prepare();
-        }
-
+        
         $result         = $this->stmt->execute($params);
         $this->rowCount = $this->rowCount();