We don't actually use any parts of struct page; all we do is check the
value of the pointer.  So give the pointer the appropriate name & type.

Link: https://lkml.kernel.org/r/20240402201659.918308-1-willy@infradead.org


Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>