filelock: Correct the filelock owner in fcntl_setlk/fcntl_setlk64

The locks_remove_posix() function in fcntl_setlk/fcntl_setlk64 is designed
to reliably remove locks when an fcntl/close race is detected. However, it
was passing in the wrong filelock owner, it looks like a mistake and
resulting in a failure to remove locks. More critically, if the lock
removal fails, it could lead to a uaf issue while traversing the locks.

This problem occurs only in the 4.19/5.4 stable version.

Fixes: a561145f3ae9 ("filelock: Fix fcntl/close race recovery compat path")
Fixes: d30ff3304083 ("filelock: Remove locks reliably when fcntl/close race is detected")
Cc: stable@vger.kernel.org
Signed-off-by: Long Li <leo.lilong@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit a1177ea83da87a87cc352aa41f24d61c08c80b5d)
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>