Initialize the msg_flags field in all cases. This was reported by Coverity using CID 1018726.
Initialize the msg_flags field in all cases.
This was reported by Coverity using CID 1018726.

ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl