block/raw_bsd: Drop raw_is_inserted() With the new automatically-recursive implementation of bdrv_is_inserted() checking by default whether all the children of a BDS are inserted, we can drop raw's own implementation. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>