Locking: Lock cs_KeyStore instead of cs_wallet in legacy keyman

This commit only affects locking behavior and doesn't have other changes.

src/qt/test/wallettests.cpp

@@ -145,8 +145,7 @@ void TestGUI(interfaces::Node& node)
     {
         auto spk_man = wallet->GetLegacyScriptPubKeyMan();
         auto locked_chain = wallet->chain().lock();
-        LOCK(wallet->cs_wallet);
-        AssertLockHeld(spk_man->cs_wallet);
+        LOCK2(wallet->cs_wallet, spk_man->cs_KeyStore);
         wallet->SetAddressBook(GetDestinationForKey(test.coinbaseKey.GetPubKey(), wallet->m_default_address_type), "", "receive");
         spk_man->AddKeyPubKey(test.coinbaseKey, test.coinbaseKey.GetPubKey());
         wallet->SetLastBlockProcessed(105, ::ChainActive().Tip()->GetBlockHash());