Outdated Link to malloc.c

The .c file includes the same dead link as the malloc article on Doug Lea's university page (https://gee.cs.oswego.edu/dl/html/malloc.html), it can now be found at the following link:

https://gee.cs.oswego.edu/pub/misc/malloc.c
https://gee.cs.oswego.edu/pub/misc/malloc.h

The older versions can be found here:
https://gee.cs.oswego.edu/pub/misc/

The links were found on this page:
https://gee.cs.oswego.edu/dl/