nl_bridge: use set_port_stp_state in delete_inteface
nl_bridge: use set_port_stp_state in delete_inteface

Instead of manually setting the state, use the new function.

Signed-off-by: Jonas Gorski <9712c064bde5a52658fc87d6454b4956f9bf286b@bisdn.de>

bisdn/basebox,bisdn/basebox,bisdn/basebox,bisdn/basebox