It appeared, that ifconfig(8) assumes `create` keyword as hostname and tries to resolve it, when `ifconfig ifname create` invoked for already existing interface. This can produce some unexpected results, when hostname resolving successfully happened. This patch adds check that for such case.
When an interface is already exists, and `create` is only one argument, return error message. But when there are some other arguments, just remove `create` keyword from the arguments list.