Simplify condition in futility pruning
Passed STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 427040 W: 111061 L: 111271 D: 204708
Ptnml(0-2): 1709, 48524, 113171, 48500, 1616
https://tests.stockfishchess.org/tests/view/67af01d01a4c73ae1f930ea4
Passed rebased LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 28704 W: 7330 L: 7120 D: 14254
Ptnml(0-2): 8, 3000, 8138, 3186, 20
https://tests.stockfishchess.org/tests/view/67ca629a45214989aa0a123e
closes https://github.com/official-stockfish/Stockfish/pull/5924
Bench: 2050046