Update outdated comments

closes https://github.com/official-stockfish/Stockfish/pull/5158

No functional change

src/search.cpp

@@ -1083,7 +1083,7 @@ moves_loop:  // When in check, search starts here
                     extension = -1;
             }
 
-            // Recapture extensions (~0 Elo on STC, ~1 Elo on LTC)
+            // Extension for capturing the previous moved piece (~0 Elo on STC, ~1 Elo on LTC)
             else if (PvNode && move == ttMove && move.to_sq() == prevSq
                      && thisThread->captureHistory[movedPiece][move.to_sq()]
                                                   [type_of(pos.piece_on(move.to_sq()))]
@@ -1147,7 +1147,7 @@ moves_loop:  // When in check, search starts here
         {
             // 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
-            // beyond the first move depth. This may lead to hidden multiple extensions.
+            // beyond the first move depth.
             // To prevent problems when the max value is less than the min value,
             // std::clamp has been replaced by a more robust implementation.
             Depth d = std::max(1, std::min(newDepth - r, newDepth + 1));