Prepend ERROR: to all error logs

daemon/logging.h

@@ -51,7 +51,7 @@ POSSIBILITY OF SUCH DAMAGE.
 		}                                                                                          \
 	} while (0)
 
-#define PLOG_ERROR(...) fprintf(stderr, __VA_ARGS__)
+#define PLOG_ERROR(...) fprintf(stderr, "ERROR: " __VA_ARGS__)
 #define SYSLOG_ERROR(...) syslog(LOG_ERR, __VA_ARGS__)
 #define LOG_ERROR(...)                                                                             \
 	do {                                                                                           \