Specify SDT probe argument types in the probe definition itself rather than
using SDT_PROBE_ARGTYPE(). This will make it easy to extend the SDT(9) API
to allow probes with dynamically-translated types.

There is no functional change.

MFC after:	2 weeks
Fix a typo.

MFC after:	3 days
Merge branch 'master' into markj-kernel-config