python/swig: Wrap swig-sensitive struct inside #ifwdef SWIG

python/swig: Wrap swig-sensitive struct inside #ifwdef SWIG

To suppress the warnings generated by swig when parsing anonymous
struct/union, we simply wrap the offending struct/union in a
"#ifndef SWIG" statement. This is an acceptable workaround because
we don't need to generate Python bindings for these structs. In
fact, we specifically tell swig to not generate wrappers for all
structs in types.h. Although swig does not generate wrappers for
those structs, it still warns when a struct doesn't have a name
and therefore we need to use this workaround.

Signed-off-by: Martin Belanger <martin.belanger@dell.com>