net: farsync: fix the code style issue about macros

Macros with complex values should be enclosed in parentheses.
space required after that ',' .

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>