st/va: fix misplaced closing bracket

st/va: fix misplaced closing bracket

It's been like this since the code was introduced.

Fixes: 86eb4131a90 (st/va: add headless support, i.e. VA_DISPLAY_DRM)
Cc: <mesa-stable@lists.freedesktop.org>
Cc: Julien Isorce <julien.isorce@gmail.com>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Nayan Deshmukh <nayan26deshmukh@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
(cherry picked from commit aaea53c2c02e4d5352ce3d08dfd43b2676d32000)
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>