Let's factor out the code to format a help string for a property. We
are going to reuse it in qdev next, which will bring some consistency.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-25-marcandre.lureau@redhat.com>
[Adjust for removal of object_property_get_default, move default
after description. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>