scsi: target: Modify core_tmr_abort_task()

This patch modifies core_tmr_abort_task() to use same looping and locking
scheme as core_tmr_drain_state_list() does.

This frees the state_list element in se_cmd for later use by tmr
notification handling.

Note: __target_check_io_state() now is called with param 0 instead of
dev->dev_attrib.emulate_tas, because tas is not relevant since we always
get ABRT on same session like the aborted command.

Link: https://lore.kernel.org/r/20200726153510.13077-2-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>