533-randr15.t: Stop hard-coding the output name
533-randr15.t: Stop hard-coding the output name

Refactor away all mentions of DP3.

i3/i3,i3/i3,stapelberg/i3,Airblader/i3,Airblader/i3,stapelberg/i3,Airblader/i3,i3/i3,i3/i3,Airblader/i3-original,Airblader/i3-original,stapelberg/i3,Airblader/i3,Airblader/i3-original,stapelberg/i3,Airblader/i3-original,Airblader/i3-original