USB: cleanup the handling of the PM complete call

This eliminates the last instance of a function's behavior
controlled by a parameter as Linus hates such things.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>