uml: Add more specific error message on failed FindBy call

Rather than an empty failed to find, let's provide a bit more
knowledge about what we failed to find by using the name string
or the id value.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

src/uml/uml_driver.c

@@ -1385,7 +1385,8 @@ static virDomainPtr umlDomainLookupByID(virConnectPtr conn,
     umlDriverUnlock(driver);
 
     if (!vm) {
-        virReportError(VIR_ERR_NO_DOMAIN, NULL);
+        virReportError(VIR_ERR_NO_DOMAIN,
+                       _("no domain with matching id '%d'"), id);
         goto cleanup;
     }
 
@@ -1433,7 +1434,8 @@ static virDomainPtr umlDomainLookupByName(virConnectPtr conn,
     umlDriverUnlock(driver);
 
     if (!vm) {
-        virReportError(VIR_ERR_NO_DOMAIN, NULL);
+        virReportError(VIR_ERR_NO_DOMAIN,
+                       _("no domain with matching name '%s'"), name);
         goto cleanup;
     }