rename atomic level type name

include/spdlog/common.h

@@ -42,9 +42,9 @@ using sink_ptr = std::shared_ptr < sinks::sink >;
 using sinks_init_list = std::initializer_list < sink_ptr >;
 using formatter_ptr = std::shared_ptr<spdlog::formatter>;
 #if defined(SPDLOG_NO_ATOMIC_LEVELS)
-using atomic_level = details::null_atomic_int;
+using level_t = details::null_atomic_int;
 #else
-using atomic_level = std::atomic_int;
+using level_t = std::atomic_int;
 #endif
 
 //Log level enum

include/spdlog/logger.h

@@ -103,7 +103,7 @@ protected:
     std::string _name;
     std::vector<sink_ptr> _sinks;
     formatter_ptr _formatter;	
-	spdlog::atomic_level _level;
+	spdlog::level_t _level;
 };
 }