drm: Remove unused drm_device from drm_gem_object_lookup()

drm_gem_object_lookup() has never required the drm_device for its file
local translation of the user handle to the GEM object. Let's remove the
unused parameter and save some space.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: dri-devel@lists.freedesktop.org
Cc: Dave Airlie <airlied@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
[danvet: Fixup kerneldoc too.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 408d6c4..fca1cd1 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -238,9 +238,7 @@
 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
 		bool dirty, bool accessed);
 
-struct drm_gem_object *drm_gem_object_lookup(struct drm_device *dev,
-					     struct drm_file *filp,
-					     u32 handle);
+struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
 int drm_gem_dumb_destroy(struct drm_file *file,
 			 struct drm_device *dev,
 			 uint32_t handle);