xl: fix incorrect output in "help" command

In "xl help", the output includes this line:

 vsnd-list           List virtual display devices for a domain

This should obviously say "sound devices" instead of "display devices".

Signed-off-by: John E. Krokes <mag@netherworld.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>

tools/xl/xl_cmdtable.c

@@ -433,7 +433,7 @@ const struct cmd_spec cmd_table[] = {
     },
     { "vsnd-list",
       &main_vsndlist, 0, 0,
-      "List virtual display devices for a domain",
+      "List virtual sound devices for a domain",
       "<Domain(s)>",
     },
     { "vsnd-detach",