media: uvcvideo: Replace broken URL

The link to the web page that explains continued fractions is broken.
Replace it with a link to the corresponding Wikipedia page.
Reported-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/usb/uvc/uvc_driver.c

@@ -350,7 +350,7 @@ void uvc_simplify_fraction(u32 *numerator, u32 *denominator,
 
 	/*
 	 * Convert the fraction to a simple continued fraction. See
-	 * https://mathforum.org/dr.math/faq/faq.fractions.html
+	 * https://en.wikipedia.org/wiki/Continued_fraction
 	 * Stop if the current term is bigger than or equal to the given
 	 * threshold.
 	 */