This avoids warnings in some cases, and is otherwise generally good hygiene.
This feature makes it possible to toggle the gdump feature on/off during program execution, whereas the the opt.prof_dump mallctl value can only be set during program startup. This resolves #72.
Fix a regression in prof_dump_ctx() due to an uninitized variable. This was caused by revision 4f37ef693e, so no releases are affected.
4f37ef693e