overlay: Improve the horizontal fit of the charts
overlay: Improve the horizontal fit of the charts

Notably fix the fill boundary to not extend past the right hand side of
the chart.

Signed-off-by: Chris Wilson <711c73f64afdce07b7e38039a96d2224209e9a6c@chris-wilson.co.uk>

rib/intel-gpu-tools,mv0/intel-gpu-tools,dlespiau/checkmate-test-igt,tiagovignatti/intel-gpu-tools,dlespiau/checkmate-test-igt,chenxianqin/intel-gpu-tools,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools,yipdw/intel-gpu-tools,dlespiau/checkmate-test-igt,erikarn/intel-gpu-tools,mv0/intel-gpu-tools,rib/intel-gpu-tools,chenxianqin/intel-gpu-tools,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools,yipdw/intel-gpu-tools,erikarn/intel-gpu-tools,erikarn/intel-gpu-tools,rib/intel-gpu-tools,tiagovignatti/intel-gpu-tools,erikarn/intel-gpu-tools,yipdw/intel-gpu-tools,dlespiau/checkmate-test-igt,yipdw/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,rib/intel-gpu-tools