Comment # 1 on bug 1214391 from Larry Finger

I just pushed a fix to Virtualization/virtualbox. As you noted, the code is
missing an include to <net/gso.h>. The surprising part is that the definition
of skb_gso_segment is in the new place in mainline kernel 6.5-rc6, but the
header in question was applied already, thus there was no failure.

In any case, the code should now build on 6.4.10 and 6.4.11 at OBS.