netdevsim: Disable VFs on nsim_dev_reload_destroy() call

Move VFs disabling from device release() to nsim_dev_reload_destroy() to
make VFs disabling and ports removal simultaneous.
This is a requirement for VFs ports implemented in next patches.

Signed-off-by: Dmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>