Use callout_reset_sbt() instead of callout_reset() only if FreeBSD version is at least 1100048.
Hmmm. That's interesting. I'm not sure why I used 1100048. I made this change so that the driver would compile under 9.x as well as 10.x. I must have done some experiments and found that 1100048 was the magic number, but I'm not sure. I'll have to do some tests to see if I can use 1000029 instead. That is, I can do that if you think it's important. It's working with this change as is. Would you like me to try to figure out a version that makes more sense?
You should probably just use 1000029 as the version that introduced callout_reset_sbt(). I think that should work on 9, 10, and head. Since it happened before head was branched off to make stable/10, it's an accurate number for 10 and head. And the version in 9 will be less than that.