net: hns3: refactor out hclge_add_fd_entry()

mainline inclusion
from mainline-v5.13-rc1
commit 5f2b1238
category: feature
bugzilla: 173966
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5f2b1238b33c38478ddc55536b65277b30f5d456



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The process of function hclge_add_fd_entry() is complex and
prolix. To make it more readable, extract the process of
fs->ring_cookie to a single function.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Yongxin Li <liyongxin1@huawei.com>
Signed-off-by: Junxin Chen <chenjunxin1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>