USB: xhci: Fix Link TRB handoff bit twiddling.

Make sure to preserve all bits *except* the TRB_CHAIN bit when giving a
Link TRB to the hardware.  We need to save things like TRB type and the
toggle bit in the control dword.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/xhci-ring.c

@@ -188,7 +188,7 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer
 					next->link.control &= (u32) ~TRB_CYCLE;
 				else
 					next->link.control |= (u32) TRB_CYCLE;
-				next->link.control &= TRB_CHAIN;
+				next->link.control &= ~TRB_CHAIN;
 				next->link.control |= chain;
 			}
 			/* Toggle the cycle bit after the last ring segment. */