vrend: fix buffer overflow during sscanf of GLSL version

There's no need to have a temp buffer (which can overflow) when we can
explicitly ignore the preceding strings for gles hosts.

Signed-off-by: Ryan Neph <ryanneph@google.com>
Part-of: <https://gitlab.freedesktop.org/virgl/virglrenderer/-/merge_requests/972>
1 file changed