Re: [Crash-utility] Fix bug of list -h

I think the -h description should state that the address is a pointer to a "data structure containing a list_head". The "next" sentence probably doesn't belong there, because it's pretty much repeating the list_head related discussion above in help page's number "2" section. And there should probably be a caveat re: the fact that there may be a bogus structure address shown in the case of an external LIST_HEAD() or a starting list_head that's in a different data structure entirely. And most importantly, a simple but clear example should be shown.