clients: Drop deadlock circumvention hack now that we don't need it
clients: Drop deadlock circumvention hack now that we don't need it

mesa supports EGLSwapInterval 0 now, so lets remove this hack. As a
bonus we don't conflict with the XDG shell protocol that doesn't allow
committing a null-buffer, which was a side effect of this hack.

This patch reverts e9297f8e7ee09fa39b1d4293fad6e97705ccff21. See that
commit for an explanation how this worked.

Signed-off-by: Jonas Ådahl <67dcd8a17e758192e0cbb577ce1d62cc7da6cf49@gmail.com>
Reviewed-by: Derek Foreman <2f97e0f0bc172406aab8ccd42dab54c95bab8759@osg.samsung.com>
[Pekka: added reference to the original commit]
Reviewed-by: Pekka Paalanen <0f6ae7001e34c37b02fb2c1c2573ddf8f442136a@collabora.co.uk>

giucam/weston,kwm81/weston,Gnurou/weston,krezovic/weston,Gnurou/weston,krezovic/weston,Fantu/compositor-spice,sir-murray/weston,udoprog/weston,giucam/weston,kwm81/weston,Tarnyko/weston-xdg_surface_present,Fantu/compositor-spice,Fantu/compositor-spice,Tarnyko/weston-xdg_surface_present,jonnylamb/weston,udoprog/weston,xorgy/weston,xorgy/weston,jonnylamb/weston,sir-murray/weston