Optimization opportunity: don't recurse callout mutex in timeout_reset()

[Colin Percival]

At 20:28 04/08/2004, Robert Watson wrote:
>timeout_reset() is called from the TCP code pretty frequently.  I observed
>that the callout code path is recursing the callout mutex.  Here's the KTR
>trace:
>...
>Eliminating the recursion would be beneficial, if we could.

I'll take care of this.

Colin Percival