net: hns3: clean up the build warning in debugfs by use seq file

net: hns3: clean up the build warning in debugfs by use seq file

Arnd reported that there are two build warning for on-stasck
buffer oversize. As Arnd's suggestion, using seq file way
to avoid the stack buffer or kmalloc buffer allocating.

Reported-by: Arnd Bergmann <arnd@kernel.org>
Closes: https://lore.kernel.org/all/20250610092113.2639248-1-arnd@kernel.org/
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20250714061037.2616413-3-shaojijie@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>