USB: count reaches -1, tested 0

With a postfix decrement count will reach -1 rather than 0,
so the warning will not be issued.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Acked-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/pci-quirks.c

@@ -234,7 +234,7 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
 	 */
 	hcc_params = readl(base + EHCI_HCC_PARAMS);
 	offset = (hcc_params >> 8) & 0xff;
-	while (offset && count--) {
+	while (offset && --count) {
 		u32		cap;
 		int		msec;