domain_conf: Resolve resource leaks found by Valgrind
domain_conf: Resolve resource leaks found by Valgrind

https://bugzilla.redhat.com/show_bug.cgi?id=906299

Fix various resource leaks discovered while parsing through Valgrind output

(cherry picked from commit 7af7c42d05dbc8661a9905c1e32d7086f90863b6)

mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2