USB: Allow autosuspend delay to equal 0

This patch (as867) adds an entry for the new power/autosuspend
attribute in Documentation/ABI/testing, and it changes the behavior of
the delay value.  Now a delay of 0 means to autosuspend as soon as
possible, and negative values will prevent autosuspend.

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

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 12533a9..2017942 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1792,7 +1792,7 @@
 			for newly-detected USB devices (default 2).  This
 			is the time required before an idle device will be
 			autosuspended.  Devices for which the delay is set
-			to 0 won't be autosuspended at all.
+			to a negative value won't be autosuspended at all.
 
 	usbhid.mousepoll=
 			[USBHID] The interval which mice are to be polled at.