Add batch check to container stats lock

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

Closes: #1249
Approved by: rhatdan

libpod/stats.go

@@ -16,11 +16,15 @@ func (c *Container) GetContainerStats(previousStats *ContainerStats) (*Container
 	stats := new(ContainerStats)
 	stats.ContainerID = c.ID()
 	stats.Name = c.Name()
+
+	if !c.batched {
 		c.lock.Lock()
 		defer c.lock.Unlock()
 		if err := c.syncContainer(); err != nil {
 			return stats, err
 		}
+	}
+
 	if c.state.State != ContainerStateRunning {
 		return stats, nil
 	}