memory: samsung: exynos5422-dmc: handle clk_set_parent() failure

clk_set_parent() can fail and ignoring such case could lead to invalid
clock setup for given frequency.

Addresses-Coverity: Unchecked return value
Fixes: 6e7674c ("memory: Add DMC driver for Exynos5422")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20210407154535.70756-1-krzysztof.kozlowski@canonical.com

drivers/memory/samsung/exynos5422-dmc.c

@@ -1298,7 +1298,9 @@ static int exynos5_dmc_init_clks(struct exynos5_dmc *dmc)
 
 	dmc->curr_volt = target_volt;
 
-	clk_set_parent(dmc->mout_mx_mspll_ccore, dmc->mout_spll);
+	ret = clk_set_parent(dmc->mout_mx_mspll_ccore, dmc->mout_spll);
+	if (ret)
+		return ret;
 
 	clk_prepare_enable(dmc->fout_bpll);
 	clk_prepare_enable(dmc->mout_bpll);