sctp: fix to reset packet information after packet transmit

The packet information does not reset after packet transmit, this
may cause some problems such as following DATA chunk be sent without
AUTH chunk, even if the authentication of DATA chunk has been
requested by the peer.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>