scons: Fix variable not found error

Change-Id: I09708fea777a57a35e55409c8997ed0b25de2b46
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/64012
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Melissa Jost <melissakjost@gmail.com>
1 file changed