zram: remove obsolete ZRAM_DEBUG option

This config option doesn't provide any usage for zram.

Signed-off-by: Marcin Jabrzyk <[e-mail]>
Acked-by: Sergey Senozhatsky <[e-mail]>
Cc: Minchan Kim <[e-mail]>
Cc: Nitin Gupta <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/block/zram/Kconfig

···
 	help
 	  This option enables LZ4 compression algorithm support. Compression
 	  algorithm can be changed using `comp_algorithm' device attribute.
-
-config ZRAM_DEBUG
-	bool "Compressed RAM block device debug support"
-	depends on ZRAM
-	default n
-	help
-	  This option adds additional debugging code to the compressed
-	  RAM block device driver.

drivers/block/zram/zram_drv.c

···
 #define KMSG_COMPONENT "zram"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
-#ifdef CONFIG_ZRAM_DEBUG
-#define DEBUG
-#endif
-
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/bio.h>