scsi: csiostor: Remove set but not used variable 'rln'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/scsi/csiostor/csio_lnode.c: In function 'csio_ln_init':
drivers/scsi/csiostor/csio_lnode.c:1995:21: warning:
 variable 'rln' set but not used [-Wunused-but-set-variable]

It is never used since introduction, so remove it.

Link: https://lore.kernel.org/r/20191029061530.98197-1-yuehaibing@huawei.com


Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>