Simplify away smp adjustment in TT use

Passed STC
https://tests.stockfishchess.org/tests/view/62f7d81f23d42b50a8dab568
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 98160 W: 26307 L: 26165 D: 45688
Ptnml(0-2): 201, 10282, 27960, 10448, 189

Passed LTC
https://tests.stockfishchess.org/tests/view/62f8d1a623d42b50a8dad4fb
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 81544 W: 22346 L: 22200 D: 36998
Ptnml(0-2): 44, 7542, 25446, 7704, 36

closes https://github.com/official-stockfish/Stockfish/pull/4131

No functional change (single threaded).