BUG/MINOR: qpack: do not consider empty enc/dec stream as error

When parsing QPACK encoder/decoder streams, h3_decode_qcs() displays an
error trace if they are empty. Change the return code used in QPACK code
to avoid this trace.

To uniformize with MUX/H3 code, 0 is now used to indicate success.

Beyond this spurious error trace, this bug has no impact.
2 files changed