optimize log facility for multi threading

- Shorten filenames
- Add log_printf with mutex locking to play nice with Serial and two
cores

cores/esp32/esp32-hal.h

@@ -28,6 +28,7 @@ extern "C" {
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdarg.h>
 #include <inttypes.h>
 #include <string.h>
 #include <math.h>