Staging: zram: make ZRAM depends on SYSFS

We can not configure zram device without sysfs anyway, so make zram
depends on it.
Signed-off-by: NJerome Marchand <jmarchan@redhat.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/zram/Kconfig

 config ZRAM
 	tristate "Compressed RAM block device support"
-	depends on BLOCK
+	depends on BLOCK && SYSFS
 	select LZO_COMPRESS
 	select LZO_DECOMPRESS
 	default n

drivers/staging/zram/zram_drv.c

@@ -626,14 +626,12 @@ static int create_device(struct zram *zram, int device_id)
 
 	add_disk(zram->disk);
 
-#ifdef CONFIG_SYSFS
 	ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj,
 				&zram_disk_attr_group);
 	if (ret < 0) {
 		pr_warning("Error creating sysfs group");
 		goto out;
 	}
-#endif
 
 	zram->init_done = 0;
 
@@ -643,10 +641,8 @@ static int create_device(struct zram *zram, int device_id)
 
 static void destroy_device(struct zram *zram)
 {
-#ifdef CONFIG_SYSFS
 	sysfs_remove_group(&disk_to_dev(zram->disk)->kobj,
 			&zram_disk_attr_group);
-#endif
 
 	if (zram->disk) {
 		del_gendisk(zram->disk);

drivers/staging/zram/zram_sysfs.c

@@ -17,8 +17,6 @@
 
 #include "zram_drv.h"
 
-#ifdef CONFIG_SYSFS
-
 static u64 zram_stat64_read(struct zram *zram, u64 *v)
 {
 	u64 val;
@@ -220,5 +218,3 @@ static struct attribute *zram_disk_attrs[] = {
 struct attribute_group zram_disk_attr_group = {
 	.attrs = zram_disk_attrs,
 };
-
-#endif	/* CONFIG_SYSFS */