Run coin.IsSpent only once in a row

Follow-up to commit 64e4963

Author: MarcoFalke

src/validation.cpp

@@ -384,10 +384,10 @@ void CChainState::MaybeUpdateMempoolForReorg(
                 auto it2 = m_mempool->mapTx.find(txin.prevout.hash);
                 if (it2 != m_mempool->mapTx.end())
                     continue;
-                const Coin &coin = CoinsTip().AccessCoin(txin.prevout);
+                const Coin& coin{CoinsTip().AccessCoin(txin.prevout)};
                 assert(!coin.IsSpent());
                 const auto mempool_spend_height{m_chain.Tip()->nHeight + 1};
-                if (coin.IsSpent() || (coin.IsCoinBase() && mempool_spend_height - coin.nHeight < COINBASE_MATURITY)) {
+                if (coin.IsCoinBase() && mempool_spend_height - coin.nHeight < COINBASE_MATURITY) {
                     return true;
                 }
             }