net/tcp/illinois: replace broken algorithm reference link

The link to the pdf containing the algorithm description is now a
dead link; it seems http://www.ifp.illinois.edu/~srikant/ has been
moved to https://sites.google.com/a/illinois.edu/srikant/ and none of
the original papers can be found there...

I have replaced it with the only working copy I was able to find.

n.b. there is also a copy available at:

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.296.6350&rep=rep1&type=pdf

However, this seems to only be a *cached* version, so I am unsure
exactly how reliable that link can be expected to remain over time
and have decided against using that one.

Signed-off-by: Joey Pabalinas <joeypabalinas@gmail.com>

 1 file changed, 1 insertion(+), 1 deletion(-)

Signed-off-by: David S. Miller <davem@davemloft.net>