IB/srpt: Fix abort handling

Let the target core check the CMD_T_ABORTED flag instead of the SRP
target driver. Hence remove the transport_check_aborted_status()
call. Since state == SRPT_STATE_CMD_RSP_SENT is something that really
should not happen, do not try to recover if srpt_queue_response() is
called for an I/O context that is in that state. This patch is a bug
fix because the srpt_abort_cmd() call is misplaced - if that function
is called from srpt_queue_response() it should either be called
before the command state is changed or after the response has been
sent.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>