Script doesn't distinguish between standard and low-latency kernels that are installed

[wdormann]

Imagine that you have kernel and then later you decide to install the low-latency variant of that same kernel. While this script has the ability to remove kernels installed by the script, it won't help in this case. For example, from a test machine:

$ ubuntu-mainline-kernel.sh -l v5.8.3-050803 v5.8.3-050803

Ideally, the low-latency variant should be included in the name.