[PATCH] usb-storage: fix race between reset and disconnect

My recent patch converting usb-storage to use
usb_reset_composite_device() added a bug, a race between reset and
disconnect.  It was necessary to drop the private lock while executing a
reset, and if a disconnect occurs at that time it will cause a crash.

This patch (as722) fixes the problem by explicitly checking for an early
termination after executing each command.

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