usb: ftdi-elan: Convert "mutex" to semaphore

The "mutex" ftdi->sw_lock is used as a lock and a completion. Convert
it to a real semaphore which allows both.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/misc/ftdi-elan.c

@@ -2766,7 +2766,7 @@ static int ftdi_elan_probe(struct usb_interface *interface,
         ftdi->sequence_num = ++ftdi_instances;
         mutex_unlock(&ftdi_module_lock);
         ftdi_elan_init_kref(ftdi);
-        init_MUTEX(&ftdi->sw_lock);
+	semaphore_init(&ftdi->sw_lock);
         ftdi->udev = usb_get_dev(interface_to_usbdev(interface));
         ftdi->interface = interface;
         mutex_init(&ftdi->u132_lock);