serial: serial_msm: fail probe if settings clocks fails

Failure to set the clocks will causes data abort exception when
trying to write to AHB uart registers.
This patch ensures that we don't touch these registers if clock
setting failed.

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/serial/serial_msm.c

@@ -181,10 +181,12 @@ static int msm_uart_clk_init(struct udevice *dev)
 
 static int msm_serial_probe(struct udevice *dev)
 {
+	int ret;
 	struct msm_serial_data *priv = dev_get_priv(dev);
 
-	msm_uart_clk_init(dev); /* Ignore return value and hope clock was
-				  properly initialized by earlier loaders */
+	ret = msm_uart_clk_init(dev);
+	if (ret)
+		return ret;
 
 	if (readl(priv->base + UARTDM_SR) & UARTDM_SR_UART_OVERRUN)
 		writel(UARTDM_CR_CMD_RESET_ERR, priv->base + UARTDM_CR);