usbip: vhci_hcd: clear just the USB_PORT_STAT_POWER bit

Upstream commit 1c9de5bf ("usbip: vhci-hcd: Add USB3 SuperSpeed
support")

vhci_hcd clears all the bits port_status bits instead of clearing
just the USB_PORT_STAT_POWER bit when it handles ClearPortFeature:
USB_PORT_FEAT_POWER. This causes vhci_hcd attach to fail in a bad
state, leaving device unusable by the client. The device is still
attached and however client can't use it.

The problem was fixed as part of larger change to add USB3 Super Speed
support.

This patch isolates the one line fix to clear the USB_PORT_STAT_POWER
from the original patch.
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/usbip/vhci_hcd.c

@@ -285,7 +285,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 		case USB_PORT_FEAT_POWER:
 			usbip_dbg_vhci_rh(
 				" ClearPortFeature: USB_PORT_FEAT_POWER\n");
-			dum->port_status[rhport] = 0;
+			dum->port_status[rhport] &= ~USB_PORT_STAT_POWER;
 			dum->resuming = 0;
 			break;
 		case USB_PORT_FEAT_C_RESET: