skbuff: constify skb_propagate_pfmemalloc() "page" argument

mainline inclusion
from mainline-v5.12-rc1-dontuse
commit 48f971c9
category: feature
bugzilla: 173966
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=48f971c9c80a728646fc03367a28df747f20d0f4



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The function doesn't write anything to the page struct itself,
so this argument can be const.

Misc: align second argument to the brace while at it.

Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Yongxin Li <liyongxin1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>