opt: Skip checking max_weight separately

Initialize `best_selection_weight` as `max_weight` allows us to skip the
separate `max_weight` check on every loop.

src/wallet/coinselection.cpp

@@ -242,7 +242,7 @@ util::Result<SelectionResult> CoinGrinder(std::vector<OutputGroup>& utxo_pool, c
     // CoinGrinder tracks selection via the indices of the currently selected UTXOs
     std::vector<size_t> best_selection;
     CAmount best_selection_amount = MAX_MONEY;
-    int best_selection_weight = std::numeric_limits<int>::max();
+    int best_selection_weight = max_weight; // Tie is fine, because we prefer lower selection amount
     bool max_tx_weight_exceeded = false;
 
     std::vector<size_t> curr_selection;
@@ -318,15 +318,9 @@ util::Result<SelectionResult> CoinGrinder(std::vector<OutputGroup>& utxo_pool, c
         if (curr_amount + lookahead[curr_selection.back()] < selection_target + change_target) {
             // Insufficient funds with lookahead: CUT
             should_cut = true;
-        } else if (curr_weight > max_weight) {
-            // max_weight exceeded: CUT if last selected group had minimal weight, else SHIFT
-            max_tx_weight_exceeded = true;
-            if (utxo_pool[curr_selection.back()].m_weight <= min_tail_weight[curr_selection.back()]) {
-                should_cut = true;
-            } else {
-                should_shift  = true;
-            }
         } else if (curr_weight > best_selection_weight) {
+            // best_selection_weight is initialized to max_weight
+            if (curr_weight > max_weight) max_tx_weight_exceeded = true;
             // Worse weight than best solution. More UTXOs only increase weight:
             // CUT if last selected group had minimal weight, else SHIFT
             if (utxo_pool[curr_selection.back()].m_weight <= min_tail_weight[curr_selection.back()]) {