kern/95665: [if_tun] "ping: sendto: No buffer space available" with TUN interface (easily reproducable with test program)

[Bruce M. Simpson]

Gleb Smirnoff wrote:
> You didn't took it from free pool, but from me, w/o informing
> me about it before. Okay. Now, you gave up on the PR quite
> quickly, why aren't you returning it back to me?
>   

Sorry! I have been trying to push forward on things and the PR formerly 
being assigned to you got lost in the noise.
> You kept the PR in feedback state for 11 hours, and then you
> suspend the PR! Are you expecting our users to reply immediately?
>
>   
The user responded saying they could not reproduce the problem further 
as they no longer had a FreeBSD system installed. Despite my best 
efforts I could not reproduce the problem with the test case given on 
RELENG_6_1 and HEAD, as I documented in the PR.

Apologies for any confusion caused.

Best regards,
BMS