MFC r259740:
MFC r259740:

In usr.bin/sort/radixsort.c, pop_ls_mt() is only referenced if
SORT_THREADS is defined, so make the whole function conditional, instead
of just the pthread calls in it.

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