USB: Remove usages of dev->power.power_state

This patch (as922) removes all but one of the remaining vestiges of
dev->power.power_state from usbcore.  The only usage left must remain
until the deprecated "power/state" sysfs attribute is gone.

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