Correct preprocessor syntax
#define PXP_OUT_PIXEL_FORMAT kPXP_OutputPixelFormatRGB565
#define PXP_AS_PIXEL_FORMAT kPXP_AsPixelFormatRGB565
#define PXP_PS_PIXEL_FORMAT kPXP_PsPixelFormatRGB565
-#elif
+#else
#error Only 16bit color depth is supported. Set LV_COLOR_DEPTH to 16.
#endif
