account_steal_time called for idle doesn't work correctly:
1) steal time while idle needs to be added to the system time of idle
   to get correct uptime numbers
3) if there is an i/o request outstanding the steal time should be
   added to iowait, even if the hypervisor scheduled another virtual
   cpu since we are still waiting for i/o.
2) steal time while idle without an i/o request outstanding has to
   be added to cpustat->idle and not to cpustat->system.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>