libceph: fix and clarify ceph_decode_need() sizes
libceph: fix and clarify ceph_decode_need() sizes

Sum up sizeof(...) results instead of (incorrectly) hard-coding the
number of bytes, expressed in ints and longs.

Signed-off-by: Ilya Dryomov <33f1a10eef0a3354755a1541edfdb100ff87fcfc@inktank.com>
Reviewed-by: Alex Elder <f429030cf5c0faf36fac3d102073b6e63a647baa@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs