Argonne mirror is no longer available as of February 1, 2015.
Check http://mirror.anl.gov/pub/mysql/Downloads/MySQL-5.5/
The workaround consists in changing the mysql_ftp_mirror to some other mirror.
For example:
comment the variable declaration :
mysql_ftp_mirror="ftp://mirror.anl.gov/pub/mysql/Downloads/MySQL-5.5/"
Add a new value for the variable:
mysql_ftp_mirror="ftp://ftp.mirrorservice.org/sites/ftp.mysql.com/Downloads/MySQL-5.5/"
Also, the issue would have been easier to debug if the wget didn't have its stderr output redirected to /dev/null