Use correct glGetGraphicsResetStatus()
KWin loads glGetGraphicsResetStatus() on its own to handle ARB and EXT extensions. After moving graphics reset handling to the RenderBackend, kwin doesn't use its own glGetGraphicsResetStatus() function, but instead uses the one provided by libepoxy, which panics if glGetGraphicsResetStatus() is not in core spec. This change makes the OpenGLBackend use kwin's glGetGraphicsResetStatus() function instead of the one provided by libepoxy to avoid a crash.