sd/milkymist-memcard: Fix error API violation

The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL.  Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call.

milkymist_memcard_realize() is wrong that way: it passes &err to
qdev_prop_set_drive_err() and qdev_realize_and_unref().  Currently
harmless, because the latter uses it only as first argument of
error_propagate().

Making qdev_prop_set_drive_err() fail involves abuse of -global.
Leave handling that to qdev_prop_set_drive(), like we do elsewhere.

Cc: Michael Walle <[email protected]>
Signed-off-by: Markus Armbruster <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>

Author: Markus Armbruster

hw/sd/milkymist-memcard.c

@@ -279,7 +279,7 @@ static void milkymist_memcard_realize(DeviceState *dev, Error **errp)
     dinfo = drive_get_next(IF_SD);
     blk = dinfo ? blk_by_legacy_dinfo(dinfo) : NULL;
     carddev = qdev_new(TYPE_SD_CARD);
-    qdev_prop_set_drive_err(carddev, "drive", blk, &err);
+    qdev_prop_set_drive(carddev, "drive", blk);
     qdev_realize_and_unref(carddev, BUS(&s->sdbus), &err);
     if (err) {
         error_setg(errp, "failed to init SD card: %s", error_get_pretty(err));