`[[maybe_unused]]` is to be used to specify that a variable is used. Change-Id: Ife2ac96111b3af13e182baba1f3456e48c3a9f9b Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/70397 Reviewed-by: Jason Lowe-Power <power.jg@gmail.com> Maintainer: Bobby Bruce <bbruce@ucdavis.edu> Tested-by: kokoro <noreply+kokoro@google.com> Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>