scsi: qla2xxx: target: Fix offline port handling and host reset handling

Remove the function qlt_abort_cmd_on_host_reset() because it can do the
following, all of which can cause a kernel crash:

- DMA unmapping while DMA is in progress.
- Call target_execute_cmd() while DMA is in progress.
- Call transport_generic_free_cmd() while the LIO core owns a command.

Instead of trying to abort a command asynchronously, set the 'aborted' flag
and handle the abort after the hardware has passed control back to the
tcm_qla2xxx driver.

Cc: Arun Easi <arun.easi@qlogic.com>
Cc: Himanshu Madhani <hmadhani@marvell.com>
Cc: Giridhar Malavali <gmalavali@marvell.com>
Fixes: c0cb4496 ("qla2xxx: Add Host reset handling in target mode.") # v3.18.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>