-Werror=redundant-move

...now that GCC 11 trunk implements P1155R3 since <https://gcc.gnu.org/git/
?p=gcc.git;a=commit;h=1722e2013f05f1f1f99379dbaa0c0df356da731f> "c++: Implement
C++20 implicit move changes. [PR91427]", at least in -std=c++20 mode

Change-Id: Ie3c8f391fe4a6a99144ab35b2b29214ac5413fc8
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/99999
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

drawinglayer/source/processor2d/vclmetafileprocessor2d.cxx

@@ -26,6 +26,7 @@
 #include <tools/stream.hxx>
 #include <tools/diagnose_ex.h>
 #include <comphelper/processfactory.hxx>
+#include <config_global.h>
 #include <basegfx/polygon/b2dpolygonclipper.hxx>
 #include <basegfx/polygon/b2dpolypolygontools.hxx>
 #include <basegfx/polygon/b2dpolygontools.hxx>
@@ -2386,7 +2387,11 @@ VclMetafileProcessor2D::CreateBufferDevice(const basegfx::B2DRange& rCandidateRa
     else
         pBufferDevice.disposeAndClear();
 
+#if HAVE_P1155R3
+    return pBufferDevice;
+#else
     return std::move(pBufferDevice);
+#endif
 }
 
 void VclMetafileProcessor2D::processPrimitive2DOnPixelProcessor(