[Keyboard] Change default implementation for get_layer_name_user

Will now show the layer number instead of "Unknown", since this is
what will be shown if QMK Configurator is used to compile the
firmware.

keyboards/snes_macropad/snes_macropad.c

@@ -9,6 +9,8 @@ char key_name = ' ';
 uint16_t last_keycode;
 uint8_t last_row;
 uint8_t last_col;
+char layer_str[3] = ""; // 2 digits + null terminator
+_Static_assert(MAX_LAYER < 100, "layer_str is too small");
 
 static const char PROGMEM code_to_name[60] = {' ', ' ', ' ', ' ', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', 'R', 'E', 'B', 'T', '_', '-', '=', '[', ']', '\\', '#', ';', '\'', '`', ',', '.', '/', ' ', ' ', ' '};
 
@@ -58,7 +60,8 @@ static void oled_render_keylog(void) {
 }
 
 __attribute__((weak)) const char * get_layer_name_user(int layer) {
- return "Unknown";
+ snprintf(layer_str, sizeof(layer_str), "%d", layer);
+ return layer_str;
 }
 
 static void oled_render_layer(void) {