selftests: pp-bench: remove page_pool_put_page wrapper

Minor cleanup: remove the pointless looking _ wrapper around
page_pool_put_page, and just do the call directly.

Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://patch.msgid.link/20250627200501.1712389-2-almasrymina@google.com


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