Fix a couple of CTL locking issues and clean up some duplicated code.
ctl_frontend_cam_sim.c: Coalesce cfcs_online() and cfcs_offline()
into a single function since these were identical except for one line. Make sure we hold the SIM lock around path creation, and calling xpt_rescan().
scsi_ctl.c: In ctlfe_onoffline(), make sure we hold the
SIM lock around path creation and free calls, as well as xpt_action(). In ctlfe_lun_enable(), hold the SIM lock around path and peripheral operations that require it.
Sponsored by: Spectra Logic Corporation
MFC after: 1 week