net: hns3: fix some mixed type assignment

This patch cleans up some incorrect type in assignment reported by sparse
and compiler.
The warning as below:
- warning : restricted __le16 degrades to integer
- warning : cast from restricted __le32
- warning : cast from restricted __be32
- warning : cast from restricted __be16
and "mixed operation".

Signed-off-by: Guojia Liao <liaoguojia@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>