coverity#982188 unchecked return value

Change-Id: I8b99afa5d43e1a9f003c3b31175d73bf5a289232

svx/source/accessibility/AccessibleTextHelper.cxx

@@ -1633,7 +1633,19 @@ namespace accessibility
     {
 
         if( getNotifierClientId() != -1 )
-            ::comphelper::AccessibleEventNotifier::removeEventListener( getNotifierClientId(), xListener );
+        {
+            const sal_Int32 nListenerCount = ::comphelper::AccessibleEventNotifier::removeEventListener( getNotifierClientId(), xListener );
+            if ( !nListenerCount )
+            {
+                // no listeners anymore
+                // -> revoke ourself. This may lead to the notifier thread dying (if we were the last client),
+                // and at least to us not firing any events anymore, in case somebody calls
+                // NotifyAccessibleEvent, again
+                ::comphelper::AccessibleEventNotifier::TClientId nId( getNotifierClientId() );
+                mnNotifierClientId = -1;
+                ::comphelper::AccessibleEventNotifier::revokeClient( nId );
+            }
+        }
     }
 
     uno::Reference< XAccessible > SAL_CALL AccessibleTextHelper_Impl::getAccessibleAtPoint( const awt::Point& _aPoint )