--report-file fails silently

[LasneF]

when launching the command line with left right comparison

if a non valid path is provided the command line fails, but report a success

openapi-changes html-report .\b.yml .\a.yml --report-file z:\toto
SUCCESS report written to file 'z\toto:' (3259kb)

this looks related to the code line

https://github.com/pb33f/openapi-changes/blob/f520f2e9120c72973df21a0ac6a502ed8be08431/cmd/html_report.go#L282