ceph: use %zu for len in ceph_fill_inline_data()

len is size_t, should be printed with %zu.

Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
libceph: fix sparse endianness warnings

The only real issue is the one in auth_x.c and it came with
3.19-rc1 merge.

Signed-off-by: Ilya Dryomov <idryomov@redhat.com>