VMLRURegionMap.centralizedLruUpdateCallback does not always return the correct value

VMLRURegionMap.centralizedLruUpdateCallback is supposed to return the number of bytes it evicts. This is used by the caller to decide if it has done enough work.

But if centralizedLruUpdateCallback evicts more than one entry then it returns only the number of bytes in the last entry it evicted.

It should be changed to accumulate how many bytes it evicts.

This bug will impact heap percentage eviction but not memory byte eviction nor entry count eviction.