Is your feature request related to a problem? Please describe.
We recently dealt with some deadlocks due to code written in this style:

func myFunc() error {
  // do some work...
  p.Lock()
  if err := somethingThatCanPanic(); err != nil {
    p.Unlock()
    return err
  }
  p.Unlock()
  // do some more work...
  return nil
}

A safer way to write this code would be something like:

func myFunc() error {
  // do some work...
  doRiskyWork := func() error {
    p.Lock()
    defer p.Unlock()
    return somethingThatCanPanic()
  }
  if err := doRiskyWork(); err != nil {
    return err
  }
  // do some more work...
  return nil
}

It would be nice to have a lint rule that enforces .Unlock() calls on mutexes use the defer keyword, to help avoid this pitfall in the future (and identify lingering cases of it).

We recognize that in some cases, using defer is not ideal, so we should ensure that programmers have the option to use lint:ignore for this rule. However, as the organization scales, we should set the default expectation to help avoid this pattern from being used in the future.

Jira issue: CRDB-29001