net: hisilicon: Cleanup for cast to restricted __be32

This patch fixes the following warning from sparse:
hip04_eth.c:533:23: warning: cast to restricted __be16
hip04_eth.c:533:23: warning: cast to restricted __be16
hip04_eth.c:533:23: warning: cast to restricted __be16
hip04_eth.c:533:23: warning: cast to restricted __be16
hip04_eth.c:534:23: warning: cast to restricted __be32
hip04_eth.c:534:23: warning: cast to restricted __be32
hip04_eth.c:534:23: warning: cast to restricted __be32
hip04_eth.c:534:23: warning: cast to restricted __be32
hip04_eth.c:534:23: warning: cast to restricted __be32
hip04_eth.c:534:23: warning: cast to restricted __be32

Signed-off-by: Jiangfeng Xiao <xiaojiangfeng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>