cryptonote_core: fix db leak on error

src/cryptonote_core/blockchain.cpp

@@ -321,6 +321,7 @@ bool Blockchain::init(BlockchainDB* db, const bool testnet, bool offline, const
   if (!db->is_open())
   {
     LOG_ERROR("Attempted to init Blockchain with unopened DB");
+    delete db;
     return false;
   }
 

src/cryptonote_core/cryptonote_core.cpp

@@ -377,7 +377,7 @@ namespace cryptonote
     // folder might not be a directory, etc, etc
     catch (...) { }
 
-    BlockchainDB* db = new_db(db_type);
+    std::unique_ptr<BlockchainDB> db(new_db(db_type));
     if (db == NULL)
     {
       LOG_ERROR("Attempted to use non-existent database type");
@@ -468,7 +468,7 @@ namespace cryptonote
     m_blockchain_storage.set_user_options(blocks_threads,
         blocks_per_sync, sync_mode, fast_sync);
 
-    r = m_blockchain_storage.init(db, m_testnet, m_offline, test_options);
+    r = m_blockchain_storage.init(db.release(), m_testnet, m_offline, test_options);
 
     r = m_mempool.init();
     CHECK_AND_ASSERT_MES(r, false, "Failed to initialize memory pool");