[SCSI] iscsi transport: fix kernel-doc notation

Fix typo in scsi_transport_iscsi.c kernel-doc notation:

Warning(drivers/scsi/scsi_transport_iscsi.c:548): No description found for parameter 'cmd'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/scsi_transport_iscsi.c

@@ -537,7 +537,7 @@ static void iscsi_scan_session(struct work_struct *work)
 
 /**
  * iscsi_block_scsi_eh - block scsi eh until session state has transistioned
- * cmd: scsi cmd passed to scsi eh handler
+ * @cmd: scsi cmd passed to scsi eh handler
  *
  * If the session is down this function will wait for the recovery
  * timer to fire or for the session to be logged back in. If the