Back in 2009, Google began trying out one line sitelinks but it was rare to see them. Often when you see sitelinks in the Google Search results, you see them across several lines, in groups of 4 or 6 or 8.

Chris Berkley posted on Twitter that Google is showing those sitelinks in one line format again and shared a screen shot.

I am able to replicate it, here is the picture:

This is not a typical format but it may be showing up more often these days.

Forum discussion at Twitter.