Revert "ehci: make idt processing more robust"

This reverts commit 156a2e4d.

Breaks FreeBSD.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

hw/usb/hcd-ehci.c

@@ -1397,7 +1397,7 @@ static int ehci_process_itd(EHCIState *ehci,
 {
     USBDevice *dev;
     USBEndpoint *ep;
-    uint32_t i, len, pid, dir, devaddr, endp, xfers = 0;
+    uint32_t i, len, pid, dir, devaddr, endp;
     uint32_t pg, off, ptr1, ptr2, max, mult;
 
     ehci->periodic_sched_active = PERIODIC_ACTIVE;
@@ -1489,10 +1489,9 @@ static int ehci_process_itd(EHCIState *ehci,
                 ehci_raise_irq(ehci, USBSTS_INT);
             }
             itd->transact[i] &= ~ITD_XACT_ACTIVE;
-            xfers++;
         }
     }
-    return xfers ? 0 : -1;
+    return 0;
 }