uml: Create accessors to virDomainObjListFindByUUID
uml: Create accessors to virDomainObjListFindByUUID

Rather than repeat code throughout, create and use a couple of
accessors in order to lookup by UUID. This will also generate
a common error message including the failed uuidstr for lookup
rather than just returning nothing in some instances.

Signed-off-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>
Reviewed-by: Daniel P. Berrangé <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

crobinso/libvirt,crobinso/libvirt,olafhering/libvirt,nertpinx/libvirt,andreabolognani/libvirt,jfehlig/libvirt,jardasgit/libvirt,jardasgit/libvirt,zippy2/libvirt,nertpinx/libvirt,eskultety/libvirt,andreabolognani/libvirt,zippy2/libvirt,nertpinx/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,libvirt/libvirt,crobinso/libvirt,zippy2/libvirt,eskultety/libvirt,crobinso/libvirt,eskultety/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,jfehlig/libvirt,libvirt/libvirt,jardasgit/libvirt,eskultety/libvirt,libvirt/libvirt,andreabolognani/libvirt,olafhering/libvirt,jardasgit/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,libvirt/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,olafhering/libvirt,olafhering/libvirt,nertpinx/libvirt,eskultety/libvirt,fabianfreyer/libvirt,zippy2/libvirt