io_uring: do not recycle buffer in READV

READV cannot recycle buffers as it would lose some of the data required to
reimport that buffer.

Reported-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Fixes: b66e65f4

 ("io_uring: never call io_buffer_select() for a buffer re-select")
Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220721131325.624788-1-dylany@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>