fixes the off by one errors in examples/screenshot
fixes the off by one errors in examples/screenshot

The inverse loop iterations for the transformed outputs had an off by
one error, iterating 1 based, not 0 based. This commit fixes that.

ascent12/wlroots,swaywm/wlroots,ascent12/wlroots,swaywm/wlroots,SirCmpwn/wlroots