Simple(?) question

[Roland McGrath]

> semantic error: unsupported type tag 19: identifier '$q' at 
> adb-timo-hist.stp:7:14
> semantic error: probe_1462 with invalid type long for operator '.' at 
> adb-timo-hist.stp:7:20

I think this is systemtap's unhelpful way of saying that $q was being used
in a fetch, but it thinks it has a struct type.  I thought this might be a
syntactical precedence issue, so "<<< ($q->...)" would work.  But $q is
actually a pointer type, so I'm not sure that's what's going on.