Removal of kern_xxx() no-at variants.

[John Baldwin]

On Wednesday, November 12, 2014 8:24:52 am Konstantin Belousov wrote:
> We have 'fat' KPI for kern_open() and other vfs syscall helpers, after
> the at-version of the syscalls was added somewhere at 8-CURRENT.
> For instance, we provide
> 	kern_open() and kern_openat().
> But more, we provide
> 	kern_stat()
> 	kern_lstat()
> 	kern_statat()
> 	kern_statat_vhook()
> first three being a trivial wrapper around kern_statat_vhook().
> More, existence of two or (sometimes) three layers around basic
> syscall helper causes issues like r271655 making the argument
> validation split.
> 
> Kepping the compat layer was reasonable in 8-CURRENT time when the
> at variants were experimental and patch to add the syscalls was
> already large and error-prone.  Now, I think we should shave the
> extra call indirections, it costs nothing at callers and sometimes
> even improves the code.

The idea sounds fine to me.  Note that I only did a glance over the diff 
rather than a thorough review.

-- 
John Baldwin