Prevent unloading a kld for a driver that has subinterfaces (vlan and/or
wlan interfaces) from being automatically reloaded via devd shutdown
event handlers.
- Revert part of my previous changes to call ifn_stop on subinterfaces
when an interface is detached. It is better to destroy the interfaces
first so that an 'ifconfig foo0.blah down' doesn't result in ifconfig
auto-loading if_foo.ko. The ifconfig command will not be invoked if
foo0.blah is gone when ifn_stop() is called. Furthermore, it is not
necessary to explicitly invoke ifn_stop() after the subinterface is
destroyed as devd will already do that.
- Pass -n to ifconfig when destroying interfaces so that destroying a
cloned interface does not kldload any drivers.
c0bdbd5fba