mesa/main: correct requirement for EXT_occlusion_query_boolean

mesa/main: correct requirement for EXT_occlusion_query_boolean

EXT_occlusion_query_boolean require support for GL_ANY_SAMPLES_PASSED,
which ARB_occlusion_query doesn't supply. We need ARB_occlusion_query2
for this instead.

This is still not 100% accurate, as we also require support for the
GL_SAMPLES_PASSED_CONSERVATIVE target, which isn't guaranteed by either
ARB_occlusion_query nor ARB_occlusion_query2. But it should be trivial
to implement for any driver supporting ARB_occlusion_query2, as it can
simply be implemented as GL_ANY_SAMPLES_PASSED.

Signed-off-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>