scsi: cxgb4i: remove set but not used variable 'ppmax'

scsi: cxgb4i: remove set but not used variable 'ppmax'

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

drivers/scsi/cxgbi/cxgb4i/cxgb4i.c:2076:15:
 warning: variable ppmax set but not used [-Wunused-but-set-variable]
drivers/target/iscsi/cxgbit/cxgbit_ddp.c:300:15:
 warning: variable ppmax set but not used [-Wunused-but-set-variable]

It is not used since commit e563c515fb3b ("cxgb4/libcxgb/cxgb4i/cxgbit:
enable eDRAM page pods for iSCSI")

Link: https://lore.kernel.org/r/20191021142042.30964-1-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>