drm/radeon/r1xx-r4xx: don't use radeon_crtc for vblank callback

This might be called before we've allocated the radeon_crtcs

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Alex Deucher 2012-08-15 16:58:30 -04:00
commit 94f768fd74