Python 3 uses __bool__ instead of __nonzero__ when performing a Boolean comparison. Change-Id: I85185bbe136ecae67346fa23569e24edd7329222 Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/c/15996 Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>