USB: UHCI: Don't test the Short Packet Detect bit

Apparently some UHCI controllers change the value of the Short Packet
Detect (SPD) bit in the TD status word -- presumably when they receive a
short packet.  This patch (as759) changes uhci-hcd to avoid assuming
that the bit is unchanged; in fact, the driver no longer looks at SPD at
all.

This fixes the second problem reported in Bugzilla #6752.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>