io_uring/kbuf: drop 'issue_flags' from io_put_kbuf(s)() arguments

io_uring/kbuf: drop 'issue_flags' from io_put_kbuf(s)() arguments

Picking multiple buffers always requires the ring lock to be held across
the operation, so there's no need to pass in the issue_flags to
io_put_kbufs(). On the single buffer side, if the initial picking of a
ring buffer was unlocked, then it will have been committed already. For
legacy buffers, no locking is required, as they will simply be freed.

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