USB: FHCI: avoid NULL pointer dereference

Assign fhci only if usb is not NULL.
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/fhci-hcd.c

@@ -242,9 +242,10 @@ static int fhci_mem_init(struct fhci_hcd *fhci)
 static void fhci_usb_free(void *lld)
 {
 	struct fhci_usb *usb = lld;
-	struct fhci_hcd *fhci = usb->fhci;
+	struct fhci_hcd *fhci;
 
 	if (usb) {
+		fhci = usb->fhci;
 		fhci_config_transceiver(fhci, FHCI_PORT_POWER_OFF);
 		fhci_ep0_free(usb);
 		kfree(usb->actual_frame);