drm/i915: s/addr & ~PAGE_MASK/offset_in_page(addr)/

Convert our open coded offset_in_page() to the common macro.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
1 file changed