Fix awful mess of white-space issues in PsychGraphicsHardwareHALSupport.c

Only a thousand more god awful ugly formatted files to go...
PsychSetBeamposCorrection: Fix wrong crtc offsets for debug readback on NV-d0

Offsets for diagnostic readback of vblstart, vblend, vactive was wrong,
copy & paste error from NV-50. This caused some misdiagnosis of nouveau
problems.

-> Fix it so it actually has some value.
PerceptualVBLSyncTestFlipInfo.m: PerceptualVBLSyncTestFlipInfo, with extra diagnostic.

Uses the Linux-only Screen('GetFlipInfo') function for extra
diagnostics.