Currently _drbd_send_page() use sendpage_ok() in order to enable
MSG_SPLICE_PAGES, it check the first page of the iterator, the iterator
may represent contiguous pages.

MSG_SPLICE_PAGES enables skb_splice_from_iter() which checks all the
pages it sends with sendpage_ok().

When _drbd_send_page() sends an iterator that the first page is
sendable, but one of the other pages isn't skb_splice_from_iter() warns
and aborts the data transfer.

Using the new helper sendpages_ok() in order to enable MSG_SPLICE_PAGES
solves the issue.
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Signed-off-by: Ofir Gal <ofir.gal@volumez.com>
Link: https://lore.kernel.org/r/20240718084515.3833733-4-ofir.gal@volumez.comSigned-off-by: Jens Axboe <axboe@kernel.dk>