Fix the contition to figure whenever we need to wait for more data or
not.  Simply check the mode, if we are not in DATAIN state any more we
are done already and don't need to go ASYNC.

Fixes: 7ad3d51ebb8a ("usb: add short-packet handling to usb-storage driver")
Reported-by: Sai Pavan Boddu <saipava@xilinx.com>
Tested-by: Paul Zimmerman <pauldzim@gmail.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb/dev-storage.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/hw/usb/dev-storage.c b/hw/usb/dev-storage.c
index 2ed6a8df2413..405a4ccfe700 100644
--- a/hw/usb/dev-storage.c
+++ b/hw/usb/dev-storage.c
@@ -546,8 +546,7 @@ static void usb_msd_handle_data(USBDevice *dev, USBPacket *p)
                     }
                 }
             }
-            if (p->actual_length < p->iov.size && (p->short_not_ok ||
-                    s->scsi_len >= p->ep->max_packet_size)) {
+            if (p->actual_length < p->iov.size && s->mode == USB_MSDM_DATAIN) {
                 DPRINTF("Deferring packet %p [wait data-in]\n", p);
                 s->packet = p;
                 p->status = USB_RET_ASYNC;
-- 
2.18.4