Update link to "Advanced Linux Programming" (#2879)

* Update link to "Advanced Linux Programming"

* Mark book as PDF

free-programming-books.md

@@ -1632,7 +1632,7 @@ Kerridge (PDF) (email address *requested*, not required)
 ### Linux
 
 * [Ad Hoc Data Analysis From The Unix Command Line](https://en.wikibooks.org/wiki/Ad_Hoc_Data_Analysis_From_The_Unix_Command_Line)
-* [Advanced Linux Programming](http://advancedlinuxprogramming.com)
+* [Advanced Linux Programming](https://mentorembedded.github.io/advancedlinuxprogramming/) (PDF)
 * [Automated Linux From Scratch](http://www.linuxfromscratch.org/alfs/download.html)
 * [Getting Started with Ubuntu](http://ubuntu-manual.org)
 * [GNU Autoconf, Automake and Libtool](http://www.sourceware.org/autobook/download.html)