db_lmdb: inline check_open, it's trivial and called everywhere

src/blockchain_db/lmdb/db_lmdb.cpp

@@ -456,6 +456,12 @@ inline int lmdb_txn_renew(MDB_txn *txn)
   return res;
 }
 
+inline void BlockchainLMDB::check_open() const
+{
+  if (!m_open)
+    throw0(DB_ERROR("DB operation attempted on a not-open DB instance"));
+}
+
 void BlockchainLMDB::do_resize(uint64_t increase_size)
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
@@ -1112,13 +1118,6 @@ void BlockchainLMDB::remove_spent_key(const crypto::key_image& k_image)
   }
 }
 
-void BlockchainLMDB::check_open() const
-{
-//  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
-  if (!m_open)
-    throw0(DB_ERROR("DB operation attempted on a not-open DB instance"));
-}
-
 BlockchainLMDB::~BlockchainLMDB()
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);

src/blockchain_db/lmdb/db_lmdb.h

@@ -357,7 +357,7 @@ private:
   virtual void check_hard_fork_info();
   virtual void drop_hard_fork_info();
 
-  void check_open() const;
+  inline void check_open() const;
 
   virtual bool is_read_only() const;