Fixed potential buffer overflow in YUV conversion

Fixes https://github.com/libsdl-org/SDL/issues/5043

src/video/yuv2rgb/yuv_rgb.c

@@ -91,7 +91,7 @@ static uint8_t clampU8(int32_t v)
 	255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
 	255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255
 	};
-	return lut[(v+128*PRECISION_FACTOR)>>PRECISION];
+	return lut[((v+128*PRECISION_FACTOR)>>PRECISION)&511];
 }