Remove a wrong FIXME

If we are there it means we already had that info stored in TT,
so we don't need to overwrite with the same content !

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/search.cpp

@@ -1534,7 +1534,7 @@ namespace {
         // Stand pat. Return immediately if static value is at least beta
         if (bestValue >= beta)
         {
-            if (!tte) // FIXME, remove condition
+            if (!tte)
                 TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, Depth(-127*OnePly), MOVE_NONE, ss->eval, ei.kingDanger[pos.side_to_move()]);
 
             return bestValue;