page_pool: fix ugly page_pool formatting

Minor cleanup; this line is badly formatted.

Signed-off-by: Mina Almasry <almasrymina@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250523230524.1107879-3-almasrymina@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>