Use blkid to find ephemeral disk on HP

HP has disk labels on their disks. This is great to make sure that we're
not trying to reformat the config drive if it's attached.

Change-Id: Ie4d96e7356893c7df7219559775196d209507059

functions.sh

@@ -253,10 +253,13 @@ function fix_disk_layout {
     # disk and mount it on /opt, syncing the previous contents of /opt
     # over.
     if [ `grep SwapTotal /proc/meminfo | awk '{ print $2; }'` -eq 0 ]; then
-        if [ -b /dev/vdb ]; then
-            DEV='/dev/vdb'
-        elif [ -b /dev/xvde ]; then
+        if [ -b /dev/xvde ]; then
             DEV='/dev/xvde'
+        else
+            EPHEMERAL_DEV=$(blkid -L ephemeral0 || true)
+            if [ -n "$EPHEMERAL_DEV" -a -b "$EPHEMERAL_DEV" ]; then
+                DEV=$EPHEMERAL_DEV
+            fi
         fi
         if [ -n "$DEV" ]; then
             local swap=${DEV}1