Simplify risk_tolerance + avoid overflow
passed simplification STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 73984 W: 19058 L: 18879 D: 36047
Ptnml(0-2): 232, 8735, 18866, 8940, 219
https://tests.stockfishchess.org/tests/view/67c269a38200cf1034c9baf9
passed simplification LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 39288 W: 10033 L: 9833 D: 19422
Ptnml(0-2): 14, 4168, 11086, 4356, 20
https://tests.stockfishchess.org/tests/view/67c34f8c8200cf1034c9bda1
closes https://github.com/official-stockfish/Stockfish/pull/5919
Bench: 2050046