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/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index b1480ac..7bc3aa6 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -333,7 +333,7 @@
 	struct ast_framebuffer *ast_fb;
 	int ret;
 
-	obj = drm_gem_object_lookup(dev, filp, mode_cmd->handles[0]);
+	obj = drm_gem_object_lookup(filp, mode_cmd->handles[0]);
 	if (obj == NULL)
 		return ERR_PTR(-ENOENT);
 
@@ -574,7 +574,7 @@
 	struct drm_gem_object *obj;
 	struct ast_bo *bo;
 
-	obj = drm_gem_object_lookup(dev, file, handle);
+	obj = drm_gem_object_lookup(file, handle);
 	if (obj == NULL)
 		return -ENOENT;