You can uninstall or removes an installed libfglrx-virtual package itself from Debian 8 (Jessie) through the terminal,
$ sudo apt-get remove libfglrx-virtual
If you would like to remove libfglrx-virtual and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove libfglrx-virtual
If you use with purge options to libfglrx-virtual package all the configuration and dependent packages will be removed.
$ sudo apt-get purge libfglrx-virtual
If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.
$ sudo apt-get purge --auto-remove libfglrx-virtual