My homemade variable power supply burns potentiometer
If shorting pins 1-2 from the pot give you an output higher than 1.25v then there I see a couple of possibilities. 

1) The diode coming across output and input pin of Lm317 is damaged or placed in the wrong direction, check if removing it solves the problem (working without this diode won't damage your circuit unless you apply inductive loads at the output). 

2) The IC may have burned and there is no regulation of 1.25v, check the voltage across your 220ohm resistor, it should always be 1.25v.

3) If none of the above solves the problem try arranging the circuit in a protoboard, if it works OK then you might have a broken trace or shortened traces in your pcb.