8250_tegra: clean up tegra_uart_handle_break

* switch "do { A; } while (1)" to "while (1) { A; }"
* switch "if (A) B; else break;" to "if (!A) break; B;"
* remove unused assignment from p->serial_in() to status

Objdump -d shows no difference.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210105120239.28031-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_tegra.c

@@ -26,16 +26,17 @@ static void tegra_uart_handle_break(struct uart_port *p)
 {
 	unsigned int status, tmout = 10000;
 
-	do {
+	while (1) {
 		status = p->serial_in(p, UART_LSR);
-		if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
-			status = p->serial_in(p, UART_RX);
-		else
+		if (!(status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS)))
 			break;
+
+		p->serial_in(p, UART_RX);
+
 		if (--tmout == 0)
 			break;
 		udelay(1);
-	} while (1);
+	}
 }
 
 static int tegra_uart_probe(struct platform_device *pdev)