mmc: dw_mmc: remove the unnecessary IS_ERR() checking for ciu/biu clock

If ciu/biu clock are NULL, clk_disable_unprepare should be just
returned. In clk_disable_unprepare(), already checked whether clk is
error or NULL.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/dw_mmc.c

@@ -3151,12 +3151,10 @@ int dw_mci_probe(struct dw_mci *host)
 		host->dma_ops->exit(host);
 
 err_clk_ciu:
-	if (!IS_ERR(host->ciu_clk))
-		clk_disable_unprepare(host->ciu_clk);
+	clk_disable_unprepare(host->ciu_clk);
 
 err_clk_biu:
-	if (!IS_ERR(host->biu_clk))
-		clk_disable_unprepare(host->biu_clk);
+	clk_disable_unprepare(host->biu_clk);
 
 	return ret;
 }
@@ -3182,11 +3180,8 @@ void dw_mci_remove(struct dw_mci *host)
 	if (host->use_dma && host->dma_ops->exit)
 		host->dma_ops->exit(host);
 
-	if (!IS_ERR(host->ciu_clk))
-		clk_disable_unprepare(host->ciu_clk);
-
-	if (!IS_ERR(host->biu_clk))
-		clk_disable_unprepare(host->biu_clk);
+	clk_disable_unprepare(host->ciu_clk);
+	clk_disable_unprepare(host->biu_clk);
 }
 EXPORT_SYMBOL(dw_mci_remove);