re: kern/45647: kill from ddb broken

[matthew green <mrg%eterna.com.au@localhost>]

> > You could probably just mutex_tryenter(&proc_lock) and print a message if 
> > it fails.
> 
> i don't think tryenter is expected to handle cases like this.
> and of course, the mutex is not an only problem.
> 
> IMO we should just close this PR.
> features like this has always been "works only if you are lucky enough".

they never work for DIAG kernels now.  it's pretty annoying.  a
"might work sometimes" fix is much better than simply failing.


.mrg.