spi/bcm63xx: check return value of clk_prepare_enable

Ensure we notice if the clock cannot be enabled for any reason and pass
the error down.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c
index e20a669..db6a47d 100644
--- a/drivers/spi/spi-bcm63xx.c
+++ b/drivers/spi/spi-bcm63xx.c
@@ -399,7 +399,10 @@
 	}
 
 	/* Initialize hardware */
-	clk_prepare_enable(bs->clk);
+	ret = clk_prepare_enable(bs->clk);
+	if (ret)
+		goto out_err;
+
 	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
 
 	/* register and we are done */
@@ -452,8 +455,11 @@
 {
 	struct spi_master *master = dev_get_drvdata(dev);
 	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+	int ret;
 
-	clk_prepare_enable(bs->clk);
+	ret = clk_prepare_enable(bs->clk);
+	if (ret)
+		return ret;
 
 	spi_master_resume(master);