net: cosa: remove redundant braces {}

This patch removes redundant braces {}, to fix the
checkpatch.pl warning:
"braces {} are not necessary for single statement blocks".

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>