jpeg/mcu: Correctly increment pixels written when decoding to graysca…

…le and dealing with interleaved images

Signed-off-by: caleb <[email protected]>

zune-jpeg/src/mcu.rs

@@ -410,7 +410,7 @@ impl<T: ZReaderTrait> JpegDecoder<T>
             )?;
 
             // increment pointer to number of pixels written
-            *pixels_written += width * out_colorspace_components * 8;
+            *pixels_written += width * out_colorspace_components * 8 * self.h_max;
         }
 
         Ok(())