USB: rename USB_SPEED_VARIABLE to USB_SPEED_WIRELESS

It's really the wireless speed, so rename the thing to make
more sense.  Based on a recommendation from David Vrabel

Cc: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 8045bc6..49f7d72 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -454,7 +454,7 @@
 	case USB_SPEED_LOW:
 		slot_ctx->dev_info |= (u32) SLOT_SPEED_LS;
 		break;
-	case USB_SPEED_VARIABLE:
+	case USB_SPEED_WIRELESS:
 		xhci_dbg(xhci, "FIXME xHCI doesn't support wireless speeds\n");
 		return -EINVAL;
 		break;
@@ -498,7 +498,7 @@
 	case USB_SPEED_LOW:
 		ep0_ctx->ep_info2 |= MAX_PACKET(8);
 		break;
-	case USB_SPEED_VARIABLE:
+	case USB_SPEED_WIRELESS:
 		xhci_dbg(xhci, "FIXME xHCI doesn't support wireless speeds\n");
 		return -EINVAL;
 		break;