GeezerVison

Checklist

• make -j4 test (UNIX), or vcbuild test nosign (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

Affected core subsystem(s)

dns

Description of change

lookupService() requires a callback function. The first commit in this PR adds a check to verify that the callback is actually a function.

As a result of the first commit, the second commit drops a pointless check. makeAsync() is an internal method in the dns module. All of the functions that call makeAsync() have already validated that the callback is a function. The second commit removes a redundant typeof function check.

lookupService() already does not work unless a function is passed, but technically the change in error message makes this a semver major. It is worth noting that currently, if you pass an object as the callback, lookupService() does not throw immediately, and instead throws in an asynchronous callback. Perhaps that is enough to convince someone that this is a bug fix and not just a semver major error message change ;-)