[Libvir] [PATCH] virConnectNumOfDefinedDomains should set virterror if cannot connect to xend

As well as $SUBJECT this also adds a comment so that the apparent lack of error in another part of the code is clear. Rich. -- Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/ Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 03798903