hmp: info migrate_capability format tunes

Dump the info in a single line is hard to read. Do it one per line.
Also, the first "capabilities:" didn't help much. Let's remove it.

CC: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: N"Dr. David Alan Gilbert" <dgilbert@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

hmp.c

@@ -268,13 +268,11 @@ void hmp_info_migrate_capabilities(Monitor *mon, const QDict *qdict)
     caps = qmp_query_migrate_capabilities(NULL);
 
     if (caps) {
-        monitor_printf(mon, "capabilities: ");
         for (cap = caps; cap; cap = cap->next) {
-            monitor_printf(mon, "%s: %s ",
+            monitor_printf(mon, "%s: %s\n",
                            MigrationCapability_lookup[cap->value->capability],
                            cap->value->state ? "on" : "off");
         }
-        monitor_printf(mon, "\n");
     }
 
     qapi_free_MigrationCapabilityStatusList(caps);