CLEANUP: traces: get rid of a few rare empty args in TRACE calls

CLEANUP: traces: get rid of a few rare empty args in TRACE calls

The TRACE macro allows to leave empty args and automatically turns them
into zeroes. However it also limits how we can remap the macro, because
functions do not accept this for example. There are very few places all
over the code where ',,' exists in TRACE calls, so let's explicitly add
the 0 there. It could even make some editors' syntax highlighting happier.