sata_sil24: remove unused variable from sata_sil24.c

The variable addr is initialized but never used
otherwise, so remove the unused variable.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch

)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>