Add the missing unlock before return from function cdns_get_id()
in the error handling case.
Fixes: ae1cca3fa347 ("serial: uartps: Change uart ID port allocation")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
        if (!alias_bitmap_initialized) {
                ret = of_alias_get_alias_list(cdns_uart_of_match, "serial",
                                              alias_bitmap, MAX_UART_INSTANCES);
-               if (ret)
+               if (ret) {
+                       mutex_unlock(&bitmap_lock);
                        return ret;
+               }
 
                alias_bitmap_initialized++;
        }