file opticial: convert to use runner's thread helpers
file opticial: convert to use runner's thread helpers

This coverts file_opticial to use runner's threading
instead of its own.

Note that the original code supported 16 threads, but per
Bryant G. Ly's request we are using nr_threads=1.

Signed-off-by: Mike Christie <39daeb1549a929782e38aa87c4e3da7f3844b09a@redhat.com>

superlibj/tcmu-runner,lxbsz/tcmu-runner,open-iscsi/tcmu-runner,JefferyHu/tcmu-runner,agrover/tcmu-runner,open-iscsi/tcmu-runner,liuy/tcmu-runner