Revert "net: page_pool: avoid false positive warning if NAPI was never added"

This reverts commit 247b420f which is
commit c1e00bc4 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I5ed1598f3985ad8b7b6de88577a980f1f87b2d0f
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>