makedirs requires and additional flag for makedirs to ignore error when the directory exists. This change enables overwriting on existing output directories for a simulation. https://docs.python.org/3/library/os.html Change-Id: I1c7329ded1f5eef2c882e3224457e1d991d074fd Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/58190 Maintainer: Jason Lowe-Power <power.jg@gmail.com> Reviewed-by: Jason Lowe-Power <power.jg@gmail.com> Tested-by: kokoro <noreply+kokoro@google.com>