fuse: notify: don't move pages

commit 0d2783626a53d4c922f82d51fa675cb5d13f0d36 upstream.

fuse_try_move_page() is not prepared for replacing pages that have already
been read.

Change-Id: Ia95e0715ef6dda98a3a435836da1606f74bcfca2
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 0d2783626a53d4c922f82d51fa675cb5d13f0d36
Git-repo: https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux-stable.git


Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>