Add auto-online test for ZED/FMA as part of the ZTS

Automated auto-online test to go along with ZED FMA integration (PR 4673)
auto_online_001.pos works with real devices (sd- and mpath) and with non-real
block devices (loop) by adding a scsi_debug device to the pool

Note: In order for test group to run, ZED must not currently be running.
Kernel 3.16.37 or higher needed for scsi_debug to work properly
If timeout occurs on test using a scsi_debug device (error noticed on Ubuntu
system), a reboot might be needed in order for test to pass. (more
investigation into this)

Also suppressed output from is_real_device/is_loop_device/is_mpath_device -
was making the log file very cluttered with useless error messages
"ie /dev/mapper/sdc is not a block device" from previous patch

Reviewed-by: Don Brady <don.brady@intel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: David Quigley <david.quigley@intel.com>
Signed-off-by: Sydney Vanda <sydney.m.vanda@intel.com>
Closes #5774