net: hns3: Add handle for default case

There are a few "switch-case" codes missed handle for default case. For
some abnormal case, it should return error code instead of return 0.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>