[PATCH] remove suspend-path recursion

This patch removes some recursion in the CONFIG_USB_SUSPEND logic, which
suspended children (of devices or hubs) that weren't already suspended.
When it sees such cases, suspend now just fails cleanly.

That logic was not needed during system-wide sleep state transitions; and
given the current notions of how to manage selective suspend transitions,
we don't want it there either.  Where it was particularly handy was coping
with various limitations of the sysfs "echo -n N > power/state" support.
(These include assuming that "N" is always meaningful to the driver; and
that drivers can only transition to state N from state zero.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>