page_pool: remove WARN_ON() with OR

Having an OR in WARN_ON() makes me sad because it's impossible to tell
which condition is true when triggered.

Split a WARN_ON() with an OR in page_pool_disable_direct_recycling().

Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>