Since truss also uses kdump's mkioctls script, pass the value of ${CPP} there too, similar to r234058.
Since truss also uses kdump's mkioctls script, pass the value of ${CPP}
there too, similar to r234058.

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