lxd/device/nic/ipvlan: Improve validation of sysctl settings when vlan setting used
lxd/device/nic/ipvlan: Improve validation of sysctl settings when vlan setting used

Signed-off-by: Thomas Parrott <6b778ce645fb0e3dde76d79eccad490955b1ae74@canonical.com>

Skarlso/lxd,lxc/lxd,lxc/lxd,lxc/lxd,mjeanson/lxd,hallyn/lxd,mjeanson/lxd,mjeanson/lxd,Skarlso/lxd,lxc/lxd,hallyn/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,Skarlso/lxd,atxwebs/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,Skarlso/lxd,atxwebs/lxd,atxwebs/lxd,stgraber/lxd,stgraber/lxd,atxwebs/lxd,hallyn/lxd,hallyn/lxd