net: hns3: fix hclge_dbg_dump_tm_pg() stack usage

This function copies strings around between multiple buffers
including a large on-stack array that causes a build warning
on 32-bit systems:

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c: In function 'hclge_dbg_dump_tm_pg':
drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:782:1: error: the frame size of 1424 bytes is larger than 1400 bytes [-Werror=frame-larger-than=]

The function can probably be cleaned up a lot, to go back to
printing directly into the output buffer, but dynamically allocating
the structure is a simpler workaround for now.

Fixes: 04d96139 ("net: hns3: refine function hclge_dbg_dump_tm_pri()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>