Fix resource leak in directshow plugin.

Add two missing release calls to free file handles.

Task-number: QTBUG-23822
Change-Id: I8f5b6d0dcf9ad66bdaa2f378c0d3e401388d7add
Reviewed-by: Wouter Huysentruit <wouter.huysentruit@dzine.be>
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>

src/plugins/directshow/player/directshowplayerservice.cpp

@@ -578,6 +578,9 @@ void DirectShowPlayerService::doReleaseGraph(QMutexLocker *locker)
         control->Release();
     }
 
+    //release m_headerInfo -> decrease ref counter of m_source
+    m_metaDataControl->updateGraph(0, 0);
+
     if (m_source) {
         m_source->Release();
         m_source = 0;
@@ -627,6 +630,7 @@ int DirectShowPlayerService::findStreamTypes(IBaseFilter *source) const
                     }
                 }
             }
+            pins->Release();
         }
         filter->Release();
     }