another finger always help
I had a similar problem and i fixed it this way:
-------------------------------1-2-3-4-4-3-2-1------------------------------
---------------------1-2-3-4--------------------4-3-2-1---------------------
-----------1-2-3-4----------------------------------------4-3-2-1-----------
-1-2-3-4------------------------------------------------------------4-3-2-1-
Between each of the notes played relax your hand, keep all your fingers on the fretboard and with your right hand slowly only lift one of the fingers at the time while keeping other fingers on the fretboard. try moving them around like you'd be giving a bird to someone, but with absolutely no muscle used in left hand.. only with the right hand.
Usually the problem isn't in the pinky itself but in middle or ring finger.
Let me know if you find this helpful.