lockd: Remove C macros that are no longer used

lockd: Remove C macros that are no longer used

The conversion of all NLMv4 procedures to xdrgen-generated
XDR functions is complete. The hand-rolled XDR size
calculation macros (Ck, No, St, Rg) and the nlm_void
structure definition served only the older implementations
and are now unused.

Also removes NLMDBG_FACILITY, which was set to the client
debug flag in server-side code but never referenced, and
corrects a comment to specify "NLMv4 Server procedures".

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>