qapi/dump: Clean up documentation of DumpGuestMemoryCapability

The type's doc comment describes its member, but it's not marked up as
such.  Easy enough to fix.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240205074709.3613229-12-armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2 files changed