Fix Y unit in Grafana dashboard

Change-Id: Id8947dad4ba7aa76dd1e9399ed5c7e9f1d49ddcb
diff --git a/ceph/files/grafana_dashboards/ceph_prometheus.json b/ceph/files/grafana_dashboards/ceph_prometheus.json
index 193e2cb..2a84c51 100644
--- a/ceph/files/grafana_dashboards/ceph_prometheus.json
+++ b/ceph/files/grafana_dashboards/ceph_prometheus.json
@@ -1277,7 +1277,7 @@
           },
           "yaxes": [
             {
-              "format": "decbytes",
+              "format": "deckbytes",
               "label": null,
               "logBase": 1,
               "max": null,
@@ -1565,4 +1565,4 @@
   "timezone": "browser",
   "title": "Ceph",
   "version": 60
-}
\ No newline at end of file
+}