qemu-option: qemu_opts_from_qdict(): use error_set()

do_device_add() and do_netdev_add() call qerror_report_err() to maintain
their QError semantics.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-By: Laszlo Ersek <lersek@redhat.com>
diff --git a/qemu-option.h b/qemu-option.h
index c0e022b..951dec3 100644
--- a/qemu-option.h
+++ b/qemu-option.h
@@ -132,7 +132,8 @@
 QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params, int permit_abbrev);
 void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
                             int permit_abbrev);
-QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict);
+QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
+                               Error **errp);
 QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict);
 
 typedef int (*qemu_opts_loopfunc)(QemuOpts *opts, void *opaque);