vrend: Fix newly introduced warnings when ENABLE_GBM_ALLOCATION is not set
In this case the paramters 'format' is not used in 'vrend_format_can_scanout' and 'gr' are not used in 'vrend_allocate_using_gbm'.
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
In this case the paramters 'format' is not used in 'vrend_format_can_scanout' and 'gr' are not used in 'vrend_allocate_using_gbm'.