Fix gce.sh destory timeouts.

test/gce.sh

@@ -36,11 +36,17 @@ function destroy {
 	names="$(vm_names)"
 	for i in {0..10}; do
 		# gcloud instances delete can sometimes hang.
-		timeout 60s /bin/bash -c "gcloud compute instances delete --zone $ZONE -q $names || true"
-		# 124 means it timed out
-		if [ $? -ne 124 ]; then
-			return
-		fi
+		case  $(set +e; timeout 60s /bin/bash -c "gcloud compute instances delete --zone $ZONE -q $names  >/dev/null 2>&1 || true"; echo $?) in
+			0)
+				return 0
+				;;
+			124)
+				# 124 means it timed out
+				break
+				;;
+			*)
+				return 1
+		esac
 	done
 }