Pivoted HostC table in Step 4 of Migrate instances.

Table now better reflects output of nova host-describe.
Also added an extra row to match typical output.

Change-Id: I46f056626a4ee5fd939856b0ff30606396502266
Implements: blueprint user-guides-reorganised
Closes-Bug: 1524389

doc/admin-guide-cloud/source/compute-live-migration-usage.rst

@@ -167,26 +167,31 @@ Before starting a migration, review the Configure migrations section.
          - PROJECT
          - cpu
          - memory_mb
-         - disk_bg
+         - disk_gb
+       * - HostC
+         - (total)
+         - 16
+         - 32232
+         - 878
        * - HostC
-         - HostC
-         - HostC
-         - HostC
-         - HostC
-       * - (total)
          - (used_now)
-         - (used_max)
+         - 22
-         - p1
-         - p2
-       * - 32232
          - 21284
-         - 21284
-         - 21284
-         - 21284
-       * - 878
          - 442
+       * - HostC
+         - (used_max)
+         - 22
+         - 21284
          - 422
+       * - HostC
+         - p1
+         - 22
+         - 21284
          - 422
+       * - HostC
+         - p2
+         - 22
+         - 21284
          - 422
 
    -  ``cpu``: Number of CPUs