Update online help and manpage to include drbd disk type.

Reviewed-by: imsnah

man/gnt-node.sgml

@@ -139,7 +139,7 @@
         This command will change the secondary node from the source
         node to the destination node for all instances having the
         source node as secondary. It works only for instances having
-        a remote raid disk layout.
+        a remote_raid1 or drbd disk layout.
       </para>
 
       <para>

scripts/gnt-node

@@ -285,7 +285,8 @@ commands = {
                [DEBUG_OPT, FORCE_OPT],
                "[-f] <src_node> <dst_node>",
                "Relocate the secondary instances from the first node"
-               " to the second one (only for instances of type remote_raid1)"),
+               " to the second one (only for instances of type remote_raid1"
+               " drbd)"),
   'failover': (FailoverNode, ARGS_ONE,
                [DEBUG_OPT, FORCE_OPT,
                 make_option("--ignore-consistency", dest="ignore_consistency",