net: hns3: package new functions to simplify hclgevf_mbx_handler code

mainline inclusion
from mainline-v5.15-rc1
commit d7517f8f
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4BY3P
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d7517f8f6b3b12c883ca0975659450ae009b1524



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This patch packages two new function to simplify the function
hclgevf_mbx_handler, and it can reduce the code cycle complexity
and make code more concise.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@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>