[media] st_rc: simplify optional reset handling

As of commit bb475230b8e5 ("reset: make optional functions really
optional"), the reset framework API calls use NULL pointers to describe
optional, non-present reset controls.

This allows to return errors from reset_control_get_optional and to call
reset_control_(de)assert unconditionally.

Signed-off-by: Philipp Zabel <[e-mail]>
Acked-by: Patrice Chotard <[e-mail]>
Signed-off-by: Sean Young <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/rc/st_rc.c

···
 	unsigned int rx_sampling_freq_div;
 
 	/* Enable the IP */
-	if (dev->rstc)
-		reset_control_deassert(dev->rstc);
+	reset_control_deassert(dev->rstc);
 
 	clk_prepare_enable(dev->sys_clock);
 	baseclock = clk_get_rate(dev->sys_clock);
···
 	else
 		rc_dev->rx_base = rc_dev->base;
 
-
 	rc_dev->rstc = reset_control_get_optional(dev, NULL);
-	if (IS_ERR(rc_dev->rstc))
-		rc_dev->rstc = NULL;
+	if (IS_ERR(rc_dev->rstc)) {
+		ret = PTR_ERR(rc_dev->rstc);
+		goto err;
+	}
 
 	rc_dev->dev = dev;
 	platform_set_drvdata(pdev, rc_dev);
···
 		writel(0x00, rc_dev->rx_base + IRB_RX_EN);
 		writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN);
 		clk_disable_unprepare(rc_dev->sys_clock);
-		if (rc_dev->rstc)
-			reset_control_assert(rc_dev->rstc);
+		reset_control_assert(rc_dev->rstc);
 	}
 
 	return 0;