driconf: fix force_gl_vendor description

The option is not a toggle to "allow GPU vendor to be overridden", it
*is* the override.

Fixes: dca119f12c291d7665d7 ("mesa/gallium: add dric option to allow overriding GL vendor string")
Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6207>
1 file changed