mm/damon/ops-common: avoid divide-by-zero during region hotness calculation

mm/damon/ops-common: avoid divide-by-zero during region hotness calculation

commit 3bafc47d3c4a2fc4d3b382aeb3c087f8fc84d9fd upstream.

When calculating the hotness of each region for the under-quota regions
prioritization, DAMON divides some values by the maximum nr_accesses.
However, due to the type of the related variables, simple division-based
calculation of the divisor can return zero.  As a result, divide-by-zero
is possible.  Fix it by using damon_max_nr_accesses(), which handles the
case.

Link: https://lkml.kernel.org/r/20231019194924.100347-4-sj@kernel.org
Fixes: 198f0f4c58b9 ("mm/damon/vaddr,paddr: support pageout prioritization")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: Jakub Acs <acsjakub@amazon.de>
Cc: <stable@vger.kernel.org>	[5.16+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>