FsLex files are reported without their path

[dawedawe]

Describe the bug
If an analyzer reports a finding in an FsLex file, only the filename is reported.

To Reproduce
Steps to reproduce the behaviour:
Run analyzers on the FSharp repo or likely any other using FsLex.

Expected behaviour
The full path to the lex.fsl file should be printed.

Screenshots

[Numpsy]

I tried running the latest version on the Fantomas source, and got relative paths printed for the fsl files there:

(Just checking if the issue still exists)