Pull my head out of my ass and actually make the tx netisr stuff work right.

Pull my head out of my ass and actually make the tx netisr stuff work right.
Do not not not call m_freem() in the txeof routines. Let the netisr routine
do it. This also makes the tx netisr queuing much simpler (I can just use
another ifqueue instead of the mess I had before.)

Thanks to Bosko Milekic for making me actually think about what I was
doing for a minute.