rhi: Fix a manual test

...that uses the old name after a recent change in the
name of a function.

Change-Id: Ife36fbb0c5d28b350cb1cfc48625528a205af8f9
Reviewed-by: Christian Strømme <christian.stromme@qt.io>

tests/manual/rhi/triquadcube/triquadcube.cpp

@@ -134,7 +134,7 @@ void Window::customInit()
     qDebug("MaxVertexOutputs: %d", m_r->resourceLimit(QRhi::MaxVertexOutputs));
 
     // With Vulkan at least we should see some details from the memory allocator.
-    qDebug() << m_r->graphicsMemoryAllocationStatistics();
+    qDebug() << m_r->statistics();
 
     // Every two seconds try printing an average of the gpu frame times.
     d.gpuFrameTimePrintTimer.start();