This was pointed out by another compiler warning. The 'name' parameter
of inquire_cred_by_mech is not a gss_name_t (which is the type of
GSS_C_NO_NAME); it's a gss_name_t *, because it's an _output_
parameter. We're not telling the library that we aren't _passing_ a
name: we're telling it that we don't need it to _return_ us a name. So
the appropriate null pointer representation is just NULL.
(This was harmless apart from a compiler warning, because gss_name_t
is a pointer type in turn and GSS_C_NO_NAME expands to a null pointer
anyway. It was just a wrongly-typed null pointer.)
This clears up another large pile of clutter at the top level, and in
the process, allows me to rename source files to things that don't all
have that annoying 'ssh' prefix at the top.
