Add EXCLUSIVE_LOCKS_REQUIRED to CWallet::ListCoins

Suggested by MarcoFalke <falke.marco@gmail.com> in
bitcoin#10605 (comment)

Author: ryanofsky

src/wallet/wallet.h

@@ -821,7 +821,7 @@ class CWallet final : public CCryptoKeyStore, public CValidationInterface
     /**
      * Return list of available coins and locked coins grouped by non-change output address.
      */
-    std::map<CTxDestination, std::vector<COutput>> ListCoins() const;
+    std::map<CTxDestination, std::vector<COutput>> ListCoins() const EXCLUSIVE_LOCKS_REQUIRED(cs_main, cs_wallet);
 
     /**
      * Find non-change parent output.