mmc: block: Init ro_lock sysfs attr to fix lockdep warnings

Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Johan Rudholm <johan.rudholm@stericsson.com>
Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/card/block.c

@@ -1694,6 +1694,7 @@ static int mmc_add_disk(struct mmc_blk_data *md)
 
 		md->power_ro_lock.show = power_ro_lock_show;
 		md->power_ro_lock.store = power_ro_lock_store;
+		sysfs_attr_init(&md->power_ro_lock.attr);
 		md->power_ro_lock.attr.mode = mode;
 		md->power_ro_lock.attr.name =
 					"ro_lock_until_next_power_on";