commit bae3f4c5 upstream.

Fix runtime PM handling of control messages by adding the required PM
counter operations.

Fixes: 11ea859d ("USB: additional power savings for cdc-acm devices
that support remote wakeup")
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>