rocker: move port stop to 'no wait' processing

rocker_port_stop can be called from atomic and non-atomic contexts.  Since
we can't test what context we're getting called in, do the processing as
'no wait', which will cover all cases.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>