Set SIGCANCEL to SIGTHR as part of some cleanup of DTrace code.
Set SIGCANCEL to SIGTHR as part of some cleanup of DTrace code.

Reviewed by:	davidxu@
MFC after:	1 week

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase