staging: zram: remove zram_sysfs

Zram sysfs needs to operate with zram devices (stats, sysfs attributes, etc.). In order to make it possible zram_drv header externs struct zram_devices and several internal functions, e.g. zram_meta_alloc/free().

Move zram sysfs code to zram drv and remove zram_sysfs.c file. This gives ability to hide exported previously struct zram_devices (along with other structs) and make a number of zram functions, used from zram sysfs, static. e.g. zram_reset_device(), etc., thus zram_drv header file becomes cleaner. We also can drop several zram_drv wrapper functions, used from zram sysfs, e.g. zram_reset_device()/__zram_reset_device() pair.

---
 drivers/staging/zram/Makefile     |   2 +-
 drivers/staging/zram/zram_drv.c   | 454 +++++++++++++++++++++++++++-----------
 drivers/staging/zram/zram_drv.h   |  12 -
 drivers/staging/zram/zram_sysfs.c | 227 -------------------
 4 files changed, 326 insertions(+), 369 deletions(-)

index 7f4a301..cb0f9ce 100644
@@ -1,3 +1,3 @@
-zram-y	:=	zram_drv.o zram_sysfs.o
+zram-y	:=	zram_drv.o
 
 obj-$(CONFIG_ZRAM)	+=	zram.o

index 2d1a3f1..dc1661b 100644
@@ -108,16 +108,4 @@ struct zram {
 
 	struct zram_stats stats;
 };
-
-extern struct zram *zram_devices;
-unsigned int zram_get_num_devices(void);
-#ifdef CONFIG_SYSFS
-extern struct attribute_group zram_disk_attr_group;
-#endif
-
-extern void zram_reset_device(struct zram *zram);
-extern struct zram_meta *zram_meta_alloc(u64 disksize);
-extern void zram_meta_free(struct zram_meta *meta);
-extern void zram_init_device(struct zram *zram, struct zram_meta *meta);
-
 #endif