CLEANUP: quic: rename quic_connection_id vars

Two different structs exists for QUIC connection ID :
* quic_connection_id which represents a full CID with its sequence
  number
* quic_cid which is just a buffer with a length. It is contained in the
  above structure.

To better differentiate them, rename all quic_connection_id variable
instances to "conn_id" by contrast to "cid" which is used for quic_cid.

This should be backported up to 2.7.
2 files changed