net:bna: fix compile warning of ‘bfa_ioc_smem_pgoff’ defined but not used

Fix the below compile warning:

drivers/net/bna/bfa_ioc.c:1922: warning: ‘bfa_ioc_smem_pgoff’ defined but not used

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>