routing: fix memory corruption in MC store

Since bbolt returns references to internally stored data when storing
locally it's best to copy the byte slices returned or alternatively
convert them to string (which also makes a copy) to avoid crashes casued
by memory corruption.

routing/missioncontrol_store.go

@@ -82,7 +82,7 @@ func newMissionControlStore(db kvdb.Backend, maxRecords int,
 		// difference when updating the DB state.
 		c := resultsBucket.ReadCursor()
 		for k, _ := c.First(); k != nil; k, _ = c.Next() {
-			keys.PushBack(k)
+			keys.PushBack(string(k))
 			keysMap[string(k)] = struct{}{}
 		}
 
@@ -334,7 +334,7 @@ func (b *missionControlStore) storeResults() error {
 				return err
 			}
 
-			keys.PushBack(k)
+			keys.PushBack(string(k))
 			keysMap[string(k)] = struct{}{}
 		}
 
@@ -345,14 +345,14 @@ func (b *missionControlStore) storeResults() error {
 			}
 
 			front := keys.Front()
-			key := front.Value.([]byte)
+			key := front.Value.(string)
 
-			if err := bucket.Delete(key); err != nil {
+			if err := bucket.Delete([]byte(key)); err != nil {
 				return err
 			}
 
 			keys.Remove(front)
-			delete(keysMap, string(key))
+			delete(keysMap, key)
 		}
 
 		return nil