Make linter point to the full compiler path

[gnikit]

Origin

in the README you are right it should not have ifort appended in the end of that path. I will fix it. In general, I think that I might just remove the tricks with the compiler paths and leave it up to the user to not pass unsafe binaries to the linter.

Originally posted by @gnikit in #492 (comment)

Explanation

Discard having to use the rootpath for the linter, instead use the path to the full binary. This will however make it possible for people to use the wrong linter binary and linter parsing expression.