Get rid of unneeded code, and refactor things a bit.
For MPA version 0 we abort the connection. For > 0, we attempt to send
an MPA_START/REJECT Reply, and then disconnect gracefully. If the send
of the MPA message fails, then we abort the connection. We can ignore
c4iw_ep_disconnect() errors here because it will clean up the endpoint
if there are failures.