regmap: adds missing braces in regmap_init()

It need to add curly braces because the inner for "if" has
two statements.

coccicheck says:
 drivers/base/regmap/regmap.c:765:2-44:
code aligned with following code on line 766
Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/base/regmap/regmap.c

@@ -760,10 +760,11 @@ struct regmap *regmap_init(struct device *dev,
 	if (ret != 0)
 		goto err_range;
 
-	if (dev)
+	if (dev) {
 		ret = regmap_attach_dev(dev, map, config);
 		if (ret != 0)
 			goto err_regcache;
+	}
 
 	return map;