drm/virtio: make mmap callback consistent with callbacks

This is a very, very minor cleanup.
Signed-off-by: NGurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20200227002601.745-2-gurchetansingh@chromium.orgSigned-off-by: NGerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/virtio/virtgpu_object.c

@@ -106,7 +106,7 @@ static const struct drm_gem_object_funcs virtio_gpu_gem_funcs = {
 	.get_sg_table = drm_gem_shmem_get_sg_table,
 	.vmap = drm_gem_shmem_vmap,
 	.vunmap = drm_gem_shmem_vunmap,
-	.mmap = &drm_gem_shmem_mmap,
+	.mmap = drm_gem_shmem_mmap,
 };
 
 struct drm_gem_object *virtio_gpu_create_object(struct drm_device *dev,