toshiba_acpi: return on a fail path

Return from bt_rfkill_poll() when hci_get_radio_state() fails.

value is invalid in that case and should not be assigned to the rfkill
state.

This also fixes a double unlock bug.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/platform/x86/toshiba_acpi.c

@@ -335,6 +335,7 @@ static void bt_rfkill_poll(struct rfkill *rfkill, void *data)
 	if (hci_result != HCI_SUCCESS) {
 		/* Can't do anything useful */
 		mutex_unlock(&dev->mutex);
+		return;
 	}
 
 	new_rfk_state = value;