Most callsites check already, one was missed.

Cc: 1653384@bugs.launchpad.net
Fixes: 94b037f2a451b3dc855f9f2c346e5049a361bd55
Reported-by: Fabian Lesniak <fabian@lesniak-it.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 1485790607-31399-2-git-send-email-kraxel@redhat.com
---
 hw/usb/hcd-xhci.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index f810678..6a1d3dc 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -2198,7 +2198,9 @@ static void xhci_kick_epctx(XHCIEPContext *epctx, unsigned int streamid)
             xhci_complete_packet(xfer);
         }
         assert(!xfer->running_retry);
-        xhci_ep_free_xfer(epctx->retry);
+        if (xfer->complete) {
+            xhci_ep_free_xfer(epctx->retry);
+        }
         epctx->retry = NULL;
     }
 
-- 
1.8.3.1