Make ucore_logging.h c++ safe

src/ucore_logging.h

@@ -60,6 +60,10 @@
  *
  */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** The log levels defined by ucore logging*/
 enum UC_LOG_LEVEL {
     UC_LL_NONE    = 0,
@@ -226,5 +230,10 @@ void uc_logf(int log_level, int module, const char *file, int line, const char *
  */
 #define UC_LOGF(lvl, mod, fmt, ...) uc_logf(lvl, mod, __FILE__, __LINE__, fmt, ## __VA_ARGS__)
 
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif