Fix potential segfault on malformed XML
Fix potential segfault on malformed XML

ovirt_resource_set_{actions,sub_collections}_from_xml warn if
link_node->name is NULL, but then call strcmp() on it anyway, which
would cause a crash. Use g_strcpm0() instead to avoid the crash.
The rest of the code will safely handle a NULL link_node->name.

This issue was reported by Coverity.

etrunko/libgovirt,etrunko/libgovirt,GNOME/libgovirt