Remove unused variable td from sched_idletd().
Remove unused variable td from sched_idletd().

MFC after:	3 days
Found with:	Coverity Prevent(tm)
CID:		3561

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