eth: fbnic: access @pp through netmem_desc instead of page

To eliminate the use of struct page in page pool, the page pool users
should use netmem descriptor and APIs instead.

Make fbnic access @pp through netmem_desc instead of page.

Signed-off-by: Byungchul Park <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/meta/fbnic/fbnic_txrx.c

···
 				 FBNIC_TWD_TYPE_AL;
 		total_bytes += FIELD_GET(FBNIC_TWD_LEN_MASK, twd);
 
-		page_pool_put_page(page->pp, page, -1, pp_allow_direct);
+		page_pool_put_page(pp_page_to_nmdesc(page)->pp, page, -1,
+				   pp_allow_direct);
 next_desc:
 		head++;
 		head &= ring->size_mask;