After checking SR5 core and Street Grimoire in regards to the adept powers gained from mentor spirits. I can't find what happens when an adept gains a mentor spirit after character creation that grants powers that the adept already has.
Example. Adept has Killing Hands and later gains the Shark MS (SR5 p323), which grants free Killing Hands.
Does the adept regain the power points spent on that power to redistribute as they see fit?
Normally, when you gain a power that you already have, you simply increase it's ranks. Killing Hands, however, does not have ranks, so GM discretion is needed here.
"Spend points elsewhere" is a valid choice, even thought it is not normally allowed by the rules, it is not totally frowned upon alternative by the author of adepts.
As GM, i would replace Killing Hands by another, more appropriate power to a "Shark Adept", like:
Improved Sense (Smell), and give him a sonar-like sense.
Blind Fighting, so he can find and fight enemies by smell.
Spirit Claw, properly re-flavored as jaws, so they can better fight spirits.
