Fix a couple of epydoc warnings

It seems epydoc needs fully-qualified references, and doesn't deal with
relative ones (not even in the current module) if there are any
ambiguities.

There are other epydoc warnings, in the rapi docstrings, but those are
left as-is as they're removed in 2.1.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>