Remove the moveCount increase in the LMR condition.

Passed non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 87104 W: 22630 L: 22464 D: 42010
Ptnml(0-2): 316, 10295, 22132, 10525, 284
https://tests.stockfishchess.org/tests/view/66dccd00dc53972b68218c60

Passed non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 94050 W: 23869 L: 23722 D: 46459
Ptnml(0-2): 49, 10400, 25985, 10537, 54
https://tests.stockfishchess.org/tests/view/66dd69c7dc53972b68218ca5

closes official-stockfish#5582

Bench: 1281840

src/search.cpp

@@ -1159,7 +1159,7 @@ Value Search::Worker::search(
         r -= ss->statScore / 10898;
 
         // Step 17. Late moves reduction / extension (LMR, ~117 Elo)
-        if (depth >= 2 && moveCount > 1 + (rootNode && depth < 10))
+        if (depth >= 2 && moveCount > 1)
         {
             // In general we want to cap the LMR depth search at newDepth, but when
             // reduction is negative, we allow this move a limited search extension