Remove useless razoring condition

STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 20626 W: 3977 L: 3855 D: 12794

LTC:
LLR: 3.10 (-2.94,2.94) [-3.00,1.00]
Total: 87334 W: 13675 L: 13648 D: 60011

Retire also the now unused pawn_on_7th() helper.

bench: 8248166

src/movepick.h

@@ -32,7 +32,7 @@
 /// The Stats struct stores moves statistics. According to the template parameter
 /// the class can store History and Countermoves. History records how often
 /// different moves have been successful or unsuccessful during the current search
-/// and is used for reduction and move ordering decisions. 
+/// and is used for reduction and move ordering decisions.
 /// Countermoves store the move that refute a previous one. Entries are stored
 /// using only the moving piece and destination square, hence two moves with
 /// different origin but same destination and piece will be considered identical.
@@ -54,7 +54,7 @@ struct Stats {
   void update(Piece pc, Square to, Value v) {
 
     if (abs(table[pc][to] + v) < Max)
-        table[pc][to] +=  v;
+        table[pc][to] += v;
   }
 
 private:

src/position.h

@@ -141,7 +141,6 @@ class Position {
 
   // Piece specific
   bool pawn_passed(Color c, Square s) const;
-  bool pawn_on_7th(Color c) const;
   bool opposite_bishops() const;
 
   // Doing and undoing moves
@@ -366,10 +365,6 @@ inline bool Position::opposite_bishops() const {
         && opposite_colors(pieceList[WHITE][BISHOP][0], pieceList[BLACK][BISHOP][0]);
 }
 
-inline bool Position::pawn_on_7th(Color c) const {
-  return pieces(c, PAWN) & rank_bb(relative_rank(c, RANK_7));
-}
-
 inline bool Position::is_chess960() const {
   return chess960;
 }

src/search.cpp

@@ -674,8 +674,7 @@ namespace {
     if (   !PvNode
         &&  depth < 4 * ONE_PLY
         &&  eval + razor_margin(depth) <= alpha
-        &&  ttMove == MOVE_NONE
-        && !pos.pawn_on_7th(pos.side_to_move()))
+        &&  ttMove == MOVE_NONE)
     {
         if (   depth <= ONE_PLY
             && eval + razor_margin(3 * ONE_PLY) <= alpha)