MINOR: quic: do not manage connection in xprt snd_buf

Remove usage of connection in quic_conn_from_buf. As connection and
quic_conn are decorrelated, it is not logical to check connection flags
when using sendto.

This require to store the L4 peer address in quic_conn to be able to use
sendto.

This change is required to delay allocation of connection.
2 files changed