mm/page_alloc: replace flag check with PageHWPoison() in check_new_page_bad()

mm/page_alloc: replace flag check with PageHWPoison() in check_new_page_bad()

This patch replaces the direct check for the __PG_HWPOISON flag with the
PageHWPoison() macro, improving code readability and maintaining
consistency with other parts of the memory management code.

Link: https://lkml.kernel.org/r/20250320063346.489030-1-ye.liu@linux.dev
Signed-off-by: Ye Liu <liuye@kylinos.cn>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>