scsi: iscsi: Fix iSCSI cls conn state

In commit 9e67600e ("scsi: iscsi: Fix race condition between login and
sync thread") I missed that libiscsi was now setting the iSCSI class state,
and that patch ended up resetting the state during conn stoppage and using
the wrong state value during ep_disconnect. This patch moves the setting of
the class state to the class module and then fixes the two issues above.

Link: https://lore.kernel.org/r/20210406171746.5016-1-michael.christie@oracle.com


Fixes: 9e67600e ("scsi: iscsi: Fix race condition between login and sync thread")
Cc: Gulam Mohamed <gulam.mohamed@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>