qdev: qdev_unplug(): use error_set()

It currently uses qerror_report(), but next commit will convert
the drive_del command to the QAPI and this requires using
error_set().

One particularity of qerror_report() is that it knows when it's
running on monitor context or command-line context and prints the
error message accordingly. error_set() doesn't do this, so we
have to be careful not to drop error messages.

qdev_unplug() has three kinds of usages:

 1. It's called when hot adding a device fails, to undo anything
    that has been done before hitting the error

 2. It's called by function monitor functions like device_del(),
    to unplug a device

 3. It's used by xen_platform.c in a way that doesn't _seem_ to
    be in monitor context

Only item 2 can print an error message to the user, this commit
maintains that.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/hw/usb/dev-storage.c b/hw/usb/dev-storage.c
index bdbe7bdd11..d865a5ef93 100644
--- a/hw/usb/dev-storage.c
+++ b/hw/usb/dev-storage.c
@@ -499,7 +499,7 @@ static void usb_msd_password_cb(void *opaque, int err)
         err = usb_device_attach(&s->dev);
 
     if (err)
-        qdev_unplug(&s->dev.qdev);
+        qdev_unplug(&s->dev.qdev, NULL);
 }
 
 static const struct SCSIBusInfo usb_msd_scsi_info = {