ceph: remove unnecessary return in switch statement

Since there's a return immediately after the 'break', there's no need for
this extra 'return' in the S_IFDIR case.

Signed-off-by: Luis Henriques <lhenriques@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>