make priority method more generic in oval struct

utils/oval/oval.go

@@ -231,8 +231,23 @@ func link(def definition) (link string) {
 }
 
 func priority(def definition) types.Priority {
-	// The OVAL files provided by SUSE doesn't include any priority/severity yet.
-	return types.Unknown
+	// Parse the priority.
+	priority := strings.TrimSpace(def.Title[strings.LastIndex(def.Title, "(")+1 : len(def.Title)-1])
+
+	// Normalize the priority.
+	switch priority {
+	case "Low":
+		return types.Low
+	case "Moderate":
+		return types.Medium
+	case "Important":
+		return types.High
+	case "Critical":
+		return types.Critical
+	default:
+		log.Warning("could not determine vulnerability priority from: %s.", priority)
+		return types.Unknown
+	}
 }
 
 func getCriterions(node criteria) [][]criterion {