greybus: interface: fix double freeing of interface structure

The interface will be released by gb_interface_release() once all
references for the interface are dropped. And so there is no need to
free it in the error path specially.
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/interface.c

@@ -167,7 +167,6 @@ struct gb_interface *gb_interface_create(struct greybus_host_device *hd,
 
 free_intf:
 	put_device(&intf->dev);
-	kfree(intf);
 put_module:
 	put_device(&module->dev);
 	return NULL;