[PATCH] aio: remove ki_retried debugging member

Remove the ki_retried member from struct kiocb.  I think the idea was
bounced around a while back, but Arnaldo pointed out another reason that we
should dig it up when he pointed out that the last cacheline of struct
kiocb only contains 4 bytes.  By removing the debugging member, we save
more than the 8 byte on 64 bit machines.

Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Acked-by: Ken Chen <kenneth.w.chen@intel.com>
Acked-by: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>