io_uring/zcrx: fix pp destruction warnings

With multiple page pools and in some other cases we can have allocated
niovs on page pool destruction. Remove a misplaced warning checking that
all niovs are returned to zcrx on io_pp_zc_destroy(). It was reported
before but apparently got lost.

Reported-by: Pedro Tammela <pctammela@mojatatu.com>
Fixes: 34a3e608 ("io_uring/zcrx: implement zerocopy receive pp memory provider")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b9e6d919d2964bc48ddbf8eb52fc9f5d118e9bc1.1751878185.git.asml.silence@gmail.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>