coverity#735874 Dereference after null check

Change-Id: I74a4a126116638aa33193f267e2f86a3c364fbae

svx/source/svdraw/svdobj.cxx

@@ -2616,10 +2616,8 @@ SdrObject* SdrObject::ConvertToContourObj(SdrObject* pRet, bool bForceLineDash)
     }
     else
     {
-        if(pRet && dynamic_cast<const SdrPathObj*>( pRet) !=  nullptr)
+        if (SdrPathObj *pPathObj = dynamic_cast<SdrPathObj*>(pRet))
         {
-            SdrPathObj* pPathObj = static_cast<SdrPathObj*>(pRet);
-
             // bezier geometry got created, even for straight edges since the given
             // object is a result of DoConvertToPolyObj. For conversion to contour
             // this is not really needed and can be reduced again AFAP