UPSTREAM: io_uring: correct pinned_vm accounting

[ upstream commit 42b6419d ]

->mm_account should be released only after we free all registered
buffers, otherwise __io_sqe_buffers_unregister() will see a NULL
->mm_account and skip locked_vm accounting.

Bug: 268174392
Cc: <Stable@vger.kernel.org>
Change-Id: I4cb5b8bcd1d87a631fd0de3227007d09b8ffff7f
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6d798f65ed4ab8db3664c4d3397d4af16ca98846.1664849932.git.asml.silence@gmail.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 67cbc886)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>