not close critical section at uma_core.c

[Konstantin Belousov]

On Tue, Feb 06, 2018 at 03:00:23PM +0900, Mori Hiroki wrote:
> Hi
> 
> I'm still debugging armv5t.
> 
> I found not good code in vm/uma_core.c. This critical_enter  have no critical_exit.
> 
> https://svnweb.freebsd.org/base/head/sys/vm/uma_core.c?revision=328916&view=markup#l2344
> 
The code path is convoluted, but each critical_enter() in the
uma_zalloc_arg() function is accompanied by the goto zalloc_start;, and
there the conditions are prepared by an origin site to enter the if(),
which does the critical_exit().

Would critical_enter() leaked in so often used function, locking operations
started panicing a lot.