serial: imx: Switch setting dma_is_txing from "false" to "0"

The variable "dma_is_txing" is an unsigned int, set as either "0" or "1"
in all but one location, where it is instead set to "false". For
consistency, set dma_is_txing to "0" in this location too.

Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/imx.c

@@ -1412,7 +1412,7 @@ static void imx_flush_buffer(struct uart_port *port)
 		temp = readl(sport->port.membase + UCR1);
 		temp &= ~UCR1_TDMAEN;
 		writel(temp, sport->port.membase + UCR1);
-		sport->dma_is_txing = false;
+		sport->dma_is_txing = 0;
 	}
 
 	/*