xwm: fix extra break

The first break in TYPE_WM_PROTOCOLS was almost certainly intended to be
nested within the if statement.

Even if it wasn't, it makes sense there.

Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
1 file changed