Using BSD licensed code in a GPL program

I need to borrow a structure and an array definition from mount.c (https://github.com/openbsd/src/blob/27d3e8ada1f03120e88616f430372e9617e250b1/sbin/mount/mount.c#L74).

Do I need to include BSD license header and The Regents of the University of California copyright somewhere? If yes, how should I do this given that the rest of the code in the modified file is GPL.

Or is it better to rewrite it?