The MM tracepoint for page free (called kmem:mm_page_free) doesn't provide
the page pointer directly, instead it provides the PFN (Page Frame Number).
This is annoying when writing a page_pool leak detector in BPF.

This patch change page_pool tracepoints to also provide the PFN.
The page pointer is still provided to allow other kinds of
troubleshooting from BPF.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>