present/scmd: Check that the flip and screen pixmap pitches match
If they don't, flipping will result in corrupted display. Test case: * Run Xorg at 1920x1080 with no window manager * glxgears -geometry 2048x1080
If they don't, flipping will result in corrupted display. Test case: * Run Xorg at 1920x1080 with no window manager * glxgears -geometry 2048x1080