Fix off by one error

ConflictSet.cpp

@@ -826,7 +826,7 @@ int getChildLeq(Node *self, int child) {
       uint64_t word;
       memcpy(&word, nonNull, kUnrollCount);
       if (word) {
-        return i + 8 - __builtin_clzll(word) / 8;
+        return i + 7 - __builtin_clzll(word) / 8;
       }
     }
 #else