net: wan: remove redundant braces {}

Braces {} are not necessary for single statement blocks,
this patch removes redundant braces {}.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>