net: hns3: modify handling of out of memory in hclge_err.c

Users should be informed if HNS driver failed to allocate memory for
descriptor when handling hw errors. This patch solve above issues.

Signed-off-by: Weihang Li <liweihang@hisilicon.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>