how-to-use-virtio-mem-with-kata.md: Remove undefined ${REPORT_DIR}
Remove undefined ${REPORT_DIR} in how-to-use-virtio-mem-with-kata.md.
Fixes:
@@ -41,7 +41,7 @@ $ echo 1 | sudo tee /proc/sys/vm/overcommit_memory
Use following command to start a Kata Container.
```
$ pod_yaml=pod.yaml
-$ container_yaml=${REPORT_DIR}/container.yaml
+$ container_yaml=container.yaml
$ image="quay.io/prometheus/busybox:latest"
$ cat << EOF > "${pod_yaml}"
metadata:
