fixes pointer issue

Author: kdschlosser

ext_mod/lcd_bus/esp32_include/rgb565_dither.h

@@ -11,9 +11,9 @@
 
     static inline rgb565_dither_pixel(uint8_t treshold_id, uint16_t *pixel)
     {
-        *pixel = (((((pixel >> 8) & 0xF8) + red_thresh[treshold_id]) << 8) |
-                  ((((pixel >> 3) & 0xFC) + green_thresh[treshold_id]) << 3) |
-                  ((((pixel & 0x1F) << 3) + blue_thresh[treshold_id]) >> 3)) ;
+        *pixel = (((((*pixel >> 8) & 0xF8) + red_thresh[treshold_id]) << 8) |
+                  ((((*pixel >> 3) & 0xFC) + green_thresh[treshold_id]) << 3) |
+                  ((((*pixel & 0x1F) << 3) + blue_thresh[treshold_id]) >> 3)) ;
     }
 
 #endif