spi/atmel: fix simple_return.cocci warnings

drivers/spi/spi-atmel.c:1518:1-4: WARNING: end returns can be simpified and declaration on line 1514 can be dropped

 Simplify a trivial if-return sequence.  Possibly combine with a
 preceding function call.
Generated by: scripts/coccinelle/misc/simple_return.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-atmel.c

@@ -1511,15 +1511,10 @@ static int atmel_spi_runtime_resume(struct device *dev)
 {
 	struct spi_master *master = dev_get_drvdata(dev);
 	struct atmel_spi *as = spi_master_get_devdata(master);
-	int ret;
 
 	pinctrl_pm_select_default_state(dev);
 
-	ret = clk_prepare_enable(as->clk);
-	if (ret)
-		return ret;
-
-	return 0;
+	return clk_prepare_enable(as->clk);
 }
 #endif