net: hns3: fix error handling int the hns3_get_vector_ring_chain

When hns3_get_vector_ring_chain() failed in the
hns3_nic_init_vector_data(), it should do the error handling instead
of return directly.

Also, cur_chain should be freed instead of chain and head->next should
be set to NULL in error handling of hns3_get_vector_ring_chain.

This patch fixes them.

Fixes: 73b907a0 ("net: hns3: bugfix for buffer not free problem during resetting")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>