mem-ruby: fix missing transition in CHI-mem

JIRA: https://gem5.atlassian.net/browse/GEM5-1195

Change-Id: I0aae4b9042cb6565c77cc8781b514a9e65ab161b
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/63676
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed