scsi: cxlflash: remove set but not used variable 'ioarcb'

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

drivers/scsi/cxlflash/main.c:47:22: warning:
 variable ioarcb set but not used [-Wunused-but-set-variable]

It is never used, so can be removed.

Link: https://lore.kernel.org/r/20191021141957.18828-1-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Matthew R. Ochs <mrochs@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>