Ok, here's my cut at a simpler page_convert_anon.  It passes Hugh and
Ingo's test cases, plus passes stress testing.

I also removed the DEBUG code in page_remove_rmap for the case where it
doesn't find anything.  This case is now definitely legal, so we shouldn't
let people shoot themselves in the foot by enabling the check.

Dave McCracken

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Dave McCracken          IBM Linux Base Kernel Team      1-512-838-3059
dmccr@us.ibm.com                                        T/L   678-3059