Revert refinedValue in ProbCut

It seems much worst in number of nodes seacrhed to reach
the depth and anyhow does not give any advantage to the
Onno's oroginal one.

So revert by now and perhaps readd when we find something
clearly better.

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

src/search.cpp

@@ -903,8 +903,9 @@ namespace {
     }
 
     // Step 9. ProbCut (is omitted in PV nodes)
-    // If we have a good capture that raises the score well above beta and a reduced
-    // search confirms the score then we can (almost) safely prune the previous move.
+    // If we have a very good capture (i.e. SEE > seeValues[captured_piece_type])
+    // and a reduced search returns a value much above beta, we can (almost) safely
+    // prune the previous move.
     if (   !PvNode
         &&  depth >= RazorDepth + ONE_PLY
         && !inCheck
@@ -917,7 +918,7 @@ namespace {
 
         assert(rdepth >= ONE_PLY);
 
-        MovePicker mp(pos, ttMove, H, Max(rbeta - refinedValue, VALUE_ZERO));
+        MovePicker mp(pos, ttMove, H, Position::see_value(pos.captured_piece_type()));
         pinned = pos.pinned_pieces(pos.side_to_move());
 
         while ((move = mp.get_next_move()) != MOVE_NONE)