util: use a single flags arg for virNetDevBandwidthSet(), not multiple bools

util: use a single flags arg for virNetDevBandwidthSet(), not multiple bools

Having two bools in the arg list is on the borderline of being
confusing to anyone trying to read the code, but we're about to add a
3rd. This patch replaces the two bools with a single flags argument
which will instead have one or more bits from virNetDevBandwidthFlags
set.

Signed-off-by: Laine Stump <laine@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>