resource-graph: Adaptive ymax
resource-graph: Adaptive ymax

For the case of data being I/O bytes written/read, we can't just assume a
particular fixed value for max on y-axis (ymax) since I/O speed varies a
lot across different hardware. The result of a fixed ymax is typically
graphs fluctuating between 0 and ymax and that is not just useless but
also looks ugly.

Lets reset ymax to the value of data point if it happens to be greater
than current ymax.

vbenes/gnome-boxes,vbenes/gnome-boxes