BUILD: quic: Fix build for m68k cross-compilation

BUILD: quic: Fix build for m68k cross-compilation

Fix several warinings as this one:

src/qmux_trace.c:80:45: error: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘uint64_t’ {aka ‘const long long unsigned int’} [-Werror=format=]
   80 |    chunk_appendf(&trace_buf, " qcs=%p .id=%lu .st=%s",
      |                                           ~~^
      |                                             |
      |                                             long unsigned int
      |                                           %llu
   81 |                  qcs, qcs->id,
      |                       ~~~~~~~
      |                          |
      |                          uint64_t {aka const long long unsigned int}
compilation terminated due to -Wfatal-errors.

Cast remaining uint64_t variables as ullong with %llu as printf format and size_t
others as ulong with %lu as printf format.

Thank you to Ilya for having reported this issue in GH #1899.

Must be backported to 2.6