Use o seguinte comando em vez do que você usou antes:
sudo apt-get purge $(dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)//")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*//;/[0-9]/!d')
Aqui está minha saída quando executo o comando acima:
saurav@saurav-P4I45Gx-PE:~$ sudo apt-get purge $(dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)//")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*//;/[0-9]/!d')
[sudo] password for saurav:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
linux-headers-3.11.0-031100* linux-headers-3.11.0-031100-generic* linux-image-3.11.0-031100-generic*
0 upgraded, 0 newly installed, 3 to remove and 39 not upgraded.
After this operation, 212 MB disk space will be freed.
Do you want to continue [Y/n]? n
Abort.
É isso aí!