ccanlint: Move ccanlint test options from _info comments to code

Currently, _info files can specify options, or note expected failures, for
ccanlint checks in the _info file with specially structured comments. That
differs from most other things ccanlint gets from _info, where it instead
executes the info file with certain parameters.

This changes ccanlint and existing _info files to use the normal method for
the ccanlint test options as well.  This also has the advantage that an
info file can alter its test options based on things from config.h - in
some cases whether a test can work or not might depend on various things.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>