ceph: use release_pages() directly
release_pages() has been available to modules since Oct, 2010,
when commit 0be8557bcd34 ("fuse: use release_pages()") added
EXPORT_SYMBOL(release_pages). However, this ceph code was still
using a workaround.
Remove the workaround, and call release_pages() directly.
Signed-off-by: John Hubbard <email@example.com>
Reviewed-by: Jeff Layton <firstname.lastname@example.org>
Signed-off-by: Ilya Dryomov <email@example.com>