[SCSI] qla4xxx: Fix multiple conn login event issue during session recovery.

[SCSI] qla4xxx: Fix multiple conn login event issue during session recovery.

During iscsid session recovery driver sends multiple ISCSI_CONN_STATE_LOGGED_IN
event from qla4xxx_conn_start() and qla4xxx_ddb_change(), which causes iscsid
to crash.

Signed-off-by: Manish Rangankar <manish.rangankar@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>