drm/irq: Coding style fix

Noticed by Thierry Reding in his review, but I've merged the drm
vblank rework topic branch a bit too quickly. So separate fixup.

Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
1 file changed