sync: Use explicit enum value
sync: Use explicit enum value

Signed-off-by: Daniel Martin <5ae2633454ceb931c1fd86ffad586b4dfc721833@gmail.com>
Reviewed-by: Ran Benita <03686f031484546e32da38cdd36b1b8bb5e2be3c@gmail.com> (and tested)
Reviewed-by: Josh Triplett <c028c213ed5efcf30c3f4fc7361dbde0c893c5b7@joshtriplett.org>

nbaum/xcb-proto,nbaum/xcb-proto