runc delete: do not ignore error from destroy

If container.Destroy() has failed, runc destroy still return 0, which is
wrong and can result in other issues down the line.

Let's always return error from destroy in runc delete.

For runc checkpoint and runc run, we still treat it as a warning.

Co-authored-by: Zhang Tianyang <burning9699@gmail.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

libcontainer/container_linux.go

@@ -874,7 +874,10 @@ func (c *Container) newInitConfig(process *Process) *initConfig {
 func (c *Container) Destroy() error {
 	c.m.Lock()
 	defer c.m.Unlock()
-	return c.state.destroy()
+	if err := c.state.destroy(); err != nil {
+		return fmt.Errorf("unable to destroy container: %w", err)
+	}
+	return nil
 }
 
 // Pause pauses the container, if its state is RUNNING or CREATED, changing