mm, hwpoison: add comment describing when to add new cases
mm, hwpoison: add comment describing when to add new cases

Here's another comment fix for hwpoison.

It describes the "guiding principle" on when to add new
memory error recovery code.

Signed-off-by: Andi Kleen <0474aee45985f5ae829f53849df476200e876990@linux.intel.com>
Acked-by: Naoya Horiguchi <8e7a128cd0264d3269a891fb3e87507c2985f8af@ah.jp.nec.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs