qemu: hotplug: fix changeable media ejection

Since return code is checked globally at the end of the function, let's
make sure that we set it correctly at any point.

This fixes a regression introduced in commit 0aa19f35 where the first
command to eject changeable media would fail unconditionally.
Signed-off-by: NBjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: NBoris Fiuczynski <fiuczy@linux.vnet.ibm.com>

src/qemu/qemu_hotplug.c

@@ -240,7 +240,8 @@ qemuDomainChangeEjectableMedia(virQEMUDriverPtr driver,
     /* If the tray is present and tray change event is supported wait for it to open. */
     if (diskPriv->tray &&
         virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE_TRAY_MOVED)) {
-        if (qemuHotplugWaitForTrayEject(driver, vm, disk, driveAlias, force) < 0)
+        rc = qemuHotplugWaitForTrayEject(driver, vm, disk, driveAlias, force);
+        if (rc < 0)
             goto error;
     } else  {
         /* otherwise report possible errors from the attempt to eject the media*/