qom: Implement qom-set HMP command

Re-implemented based on qmp_qom_set() to facilitate argument parsing.

Warn about ambiguous path arguments.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Tested-by: Alistair Francis <alistair.francis@xilinx.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/hmp.h b/hmp.h
index c5676e2..2b9308b 100644
--- a/hmp.h
+++ b/hmp.h
@@ -97,6 +97,7 @@
 void hmp_info_memdev(Monitor *mon, const QDict *qdict);
 void hmp_info_memory_devices(Monitor *mon, const QDict *qdict);
 void hmp_qom_list(Monitor *mon, const QDict *qdict);
+void hmp_qom_set(Monitor *mon, const QDict *qdict);
 void object_add_completion(ReadLineState *rs, int nb_args, const char *str);
 void object_del_completion(ReadLineState *rs, int nb_args, const char *str);
 void device_add_completion(ReadLineState *rs, int nb_args, const char *str);