fix link for "Introduction to High Performance Scientific Programming"

free-programming-books.md

@@ -486,7 +486,7 @@
 * [High Performance Computing Training](https://computing.llnl.gov/?set=training&page=index) (LLNL materials)
 * [High-Performance Scientific Computing](http://bit.ly/hpc12) (class lectures and slides)
 * [How to Write Parallel Programs](http://www.lindaspaces.com/book/)
-* [Introduction to High-Performance Scientific Computing](http://tacc-web.austin.utexas.edu/veijkhout/public_html/istc/istc.html) - Victor Eijkhout
+* [Introduction to High-Performance Scientific Computing](http://www.tacc.utexas.edu/~eijkhout/istc/istc.html) - Victor Eijkhout
 * [Introduction to Parallel Computing](https://computing.llnl.gov/tutorials/parallel_comp/) - Blaise Barney
 * [Is Parallel Programming Hard, And, If So, What Can You Do About It?](https://www.kernel.org/pub/linux/kernel/people/paulmck/perfbook/perfbook.html) - Paul E. McKenney
 * [Programming on Parallel Machines; GPU, Multicore, Clusters and More](http://heather.cs.ucdavis.edu/parprocbook) - Norm Matloff