sd: Fix "info qtree" on boards with SD cards

The SD card object is not a SysBusDevice, so don't create it with
qdev_create() if we're not assigning it to a specific bus; use
object_new() instead.

This was causing 'info qtree' to segfault on boards with SD cards,
because qdev_create(NULL, TYPE_FOO) puts the created object on the
system bus, and then we may try to run functions like sysbus_dev_print()
on it, which fail when casting the object to SysBusDevice.

(This is the same mistake that we made with the NAND device
and fixed in commit 6749695e.)
Reported-by: Nxiaoqiang.zhao <zxq_yx_007@163.com>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: Nxiaoqiang.zhao <zxq_yx_007@163.com>
Message-id: 1458061009-7733-1-git-send-email-peter.maydell@linaro.org

hw/sd/sd.c

@@ -563,17 +563,19 @@ static const VMStateDescription sd_vmstate = {
 /* Legacy initialization function for use by non-qdevified callers */
 SDState *sd_init(BlockBackend *blk, bool is_spi)
 {
+    Object *obj;
     DeviceState *dev;
     Error *err = NULL;
 
-    dev = qdev_create(NULL, TYPE_SD_CARD);
+    obj = object_new(TYPE_SD_CARD);
+    dev = DEVICE(obj);
     qdev_prop_set_drive(dev, "drive", blk, &err);
     if (err) {
         error_report("sd_init failed: %s", error_get_pretty(err));
         return NULL;
     }
     qdev_prop_set_bit(dev, "spi", is_spi);
-    object_property_set_bool(OBJECT(dev), true, "realized", &err);
+    object_property_set_bool(obj, true, "realized", &err);
     if (err) {
         error_report("sd_init failed: %s", error_get_pretty(err));
         return NULL;