Fix return value for \ThriftSQLQuery::wait()

Our docs state `\ThriftSQLQuery::wait()` returns self so that it can be chained if needed so make sure we do that.

Author: xyu

src/ThriftSQL/HiveQuery.php

@@ -48,6 +48,7 @@ public function wait() {
     }
 
     $this->_ready = true;
+    return $this;
   }
 
   public function fetch( $maxRows ) {

src/ThriftSQL/ImpalaQuery.php

@@ -52,6 +52,7 @@ public function wait() {
     } while (true);
 
     $this->_ready = true;
+    return $this;
   }
 
   public function fetch( $maxRows ) {

src/ThriftSQL/Utils/Iterator.php

@@ -96,9 +96,8 @@ public function rewind() {
     }
     $this->runCount++;
 
-    $this->thriftSQLQuery = $this->thriftSQL->query( $this->queryStr );
     $this->buffer = array();
     $this->location = 0;
-    $this->thriftSQLQuery->wait();
+    $this->thriftSQLQuery = $this->thriftSQL->query( $this->queryStr )->wait();
   }
 }