Simplified quantization table scaling in the encoder

src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs

@@ -702,19 +702,8 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
 
             for (int j = 0; j < Block8x8F.Size; j++)
             {
-                int x = unscaledQuant[j];
-                x = ((x * scale) + 50) / 100;
-                if (x < 1)
-                {
-                    x = 1;
-                }
-
-                if (x > 255)
-                {
-                    x = 255;
-                }
-
-                quant[j] = x;
+                int scaled = ((unscaledQuant[j] * scale) + 50) / 100;
+                quant[j] = Math.Clamp(scaled, 1, 255);
             }
         }
     }