scsi: qla2xxx: Fix description for parameter ql2xenforce_iocb_limit

Parameter ql2xenforce_iocb_limit is enabled by default.

Link: https://lore.kernel.org/r/20210118184922.23793-1-ematsumiya@suse.de
Fixes: 89c72f42

 ("scsi: qla2xxx: Add IOCB resource tracking")
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>