Remove obsolete logic for LRUCache size
Remove obsolete logic for LRUCache size

The LRUCache implementation has been replaced, and no longer requires a backing store larger than its capacity.
KiChjang/servo,KiChjang/servo,DominoTree/servo,larsbergstrom/servo,splav/servo,larsbergstrom/servo,splav/servo,DominoTree/servo,saneyuki/servo,splav/servo,saneyuki/servo,saneyuki/servo,splav/servo,DominoTree/servo,DominoTree/servo,KiChjang/servo,larsbergstrom/servo,KiChjang/servo,larsbergstrom/servo,saneyuki/servo,larsbergstrom/servo,DominoTree/servo,saneyuki/servo,larsbergstrom/servo,larsbergstrom/servo,KiChjang/servo,saneyuki/servo,larsbergstrom/servo,DominoTree/servo,larsbergstrom/servo,splav/servo,saneyuki/servo,DominoTree/servo,splav/servo,KiChjang/servo,saneyuki/servo,DominoTree/servo,KiChjang/servo,KiChjang/servo,KiChjang/servo,splav/servo,saneyuki/servo,splav/servo,splav/servo,DominoTree/servo,saneyuki/servo,KiChjang/servo,splav/servo,DominoTree/servo,larsbergstrom/servo