spi: spi-mxs: Check the return value from clk_prepare_enable()

clk_prepare_enable() may fail, so let's check its return value and propagate it
in the case of error.

While at it, rename 'out_free_dma' to 'out_disable_clk' so that it can properly
describe its purpose.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NMark Brown <broonie@linaro.org>

drivers/spi/spi-mxs.c

@@ -563,7 +563,10 @@ static int mxs_spi_probe(struct platform_device *pdev)
 		goto out_master_free;
 	}
 
-	clk_prepare_enable(ssp->clk);
+	ret = clk_prepare_enable(ssp->clk);
+	if (ret)
+		goto out_dma_release;
+
 	clk_set_rate(ssp->clk, clk_freq);
 	ssp->clk_rate = clk_get_rate(ssp->clk) / 1000;
 
@@ -574,13 +577,14 @@ static int mxs_spi_probe(struct platform_device *pdev)
 	ret = spi_register_master(master);
 	if (ret) {
 		dev_err(&pdev->dev, "Cannot register SPI master, %d\n", ret);
-		goto out_free_dma;
+		goto out_disable_clk;
 	}
 
 	return 0;
 
-out_free_dma:
+out_disable_clk:
 	clk_disable_unprepare(ssp->clk);
+out_dma_release:
 	dma_release_channel(ssp->dmach);
 out_master_free:
 	spi_master_put(master);