MINOR: mux-quic: replace printfs by traces

Convert all printfs in the mux-quic code with traces.

Note that some meaningul printfs were not converted because they use
extra args in a format-string. This is the case inside qcs_push_frame
and qc_send_max_streams. A dedicated trace event should be implemented
for them to be able to display the extra arguments.
1 file changed