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>

src/mem/ruby/protocol/chi/CHI-mem.sm

@@ -777,7 +777,7 @@ machine(MachineType:Memory, "Memory controller interface") :
 
   // Notice we only use this here and call wakeUp when leaving this state
   transition({READING_MEM,WAITING_NET_DATA,SENDING_NET_DATA},
-             {ReadNoSnp, ReadNoSnpSep, WriteNoSnpPtl}) {
+             {ReadNoSnp, ReadNoSnpSep, WriteNoSnpPtl, WriteNoSnp}) {
     stallRequestQueue;
   }