It seems the word is a variant of 'voodoo'. How did it come to be applied geologically? It seems no-one online has that answer.
These sources seem to suggest the geological structures are somehow unlucky:
"Possibly an alteration of voodoo or from Hausa, hu'du'ba/hu3'du3'ba1 ("to arouse resentment"). In English, meaning altered to "bring bad luck", then applied to things thought to bring bad luck, including the thin spires of rock now called hoodoos."
"Origin of hoodoo- Of West African origin, possibly from voodoo."