scsi: csiostor: remove redundant assignment to pointer 'ln'

The pointer ln is assigned a value that is never read, it is re-assigned
a new value in the list_for_each loop hence the initialization is
redundant and can be removed.

Cleans up clang warning:
drivers/scsi/csiostor/csio_lnode.c:117:21: warning: Value stored to 'ln'
during its initialization is never read

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>