file opticial: add cancelation handlers
file opticial: add cancelation handlers

Add cancelation handlers for file opticial.

Adapted from Bryant G. Ly <bryantly@linux.vnet.ibm.com>'s
patch " tcmu-runner:Fix broken file and fbo handlers"

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

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