qapi: Rename QAPISchemaAlternateType.variants to .alternatives

A previous commit narrowed the type of
QAPISchemaAlternateType.variants from QAPISchemaVariants to
QAPISchemaAlternatives.  Rename it to .alternatives.

Same for .__init__() parameter @variants.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
1 file changed