objtool segfault with ORC unwinder enabled

[Markus]

Hello!

ORC unwinder is enabled in stable for wider testing but still at least one bug 
is open:
https://bugzilla.kernel.org/show_bug.cgi?id=197035

objtool will segfault because a NULL pointer is dereferenced.

Is a NULL pointer sym valid?
If a NULL pointer is invalid, it has to be checked why it is sometimes NULL.

Thank you!
Markus