teamd: change loop callback fail to warning and add some debug messages

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
teamd: fix use after free bug in teamd_loop_callback_del()

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
1.3 release

Signed-off-by: Jiri Pirko <jiri@resnulli.us>