Comment 13 for bug 1367241

Actually I think the second approach would be better, since the error comes not from the message (which is redirected to upstart logs anyway), but from the return code of the script.

Unfortunately, according to my knowledge, the upstart scripts are executed with the "-e" switch making it stop with a failure on a first failed call. This ties our hands a bit as we cannot have any failing commands there (even those we expect to fail in a particular configuration) and makes our potential script less flexible.

So in any case we would be interested in not returning anything other than 0. A commonly used work-around for this limitation could be used like this:
modprobe -q -b vesafb || true

This would load the module if available, but would remain quiet (-q switch to modprobe with additional || true) if the module is not there.