docs: use correct hints per bus type in <disk> examples

Commit 4cf53158 tried to set up unique labels per disk in the
example, but ended up choosing strings that don't correspond
to the usual choice of bus types.  Tweak the strings once again.

* docs/formatdomain.html.in: Use preferred names.
Signed-off-by: NEric Blake <eblake@redhat.com>

docs/formatdomain.html.in

@@ -1616,12 +1616,12 @@
       <source dev='/dev/sda'/>
       <geometry cyls='16383' heads='16' secs='63' trans='lba'/>
       <blockio logical_block_size='512' physical_block_size='4096'/>
-      <target dev='sdb' bus='ide'/>
+      <target dev='hdj' bus='ide'/>
     </disk>
     <disk type='volume' device='disk'>
       <driver name='qemu' type='raw'/>
       <source pool='blk-pool0' volume='blk-pool0-vol0'/>
-      <target dev='sdc' bus='ide'/>
+      <target dev='hdk' bus='ide'/>
     </disk>
     <disk type='network' device='disk'>
       <driver name='qemu' type='raw'/>
@@ -1641,7 +1641,7 @@
       <auth username='myuser'>
         <secret type='iscsi' usage='libvirtiscsi'/>
       </auth>
-      <target dev='vdb' bus='scsi'/>
+      <target dev='sdb' bus='scsi'/>
     </disk>
     <disk type='volume' device='disk'>
       <driver name='qemu' type='raw'/>
@@ -1649,7 +1649,7 @@
       <auth username='myuser'>
         <secret type='iscsi' usage='libvirtiscsi'/>
       </auth>
-      <target dev='vdc' bus='virtio'/>
+      <target dev='vdb' bus='virtio'/>
     </disk>
     <disk type='volume' device='disk'>
       <driver name='qemu' type='raw'/>
@@ -1657,7 +1657,7 @@
       <auth username='myuser'>
         <secret type='iscsi' usage='libvirtiscsi'/>
       </auth>
-      <target dev='vdd' bus='virtio'/>
+      <target dev='vdc' bus='virtio'/>
     </disk>
     <disk type='file' device='disk'>
       <driver name='qemu' type='qcow2'/>
@@ -1671,7 +1671,7 @@
           <backingStore/>
         </backingStore>
       </backingStore>
-      <target dev='vde' bus='virtio'/>
+      <target dev='vdd' bus='virtio'/>
     </disk>
   </devices>
   ...</pre>