bcache: add static const prefix to char * array declarations

This patch declares char * array with const prefix in sysfs.c,
which is suggested by checkpatch.pl.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/bcache/sysfs.c

@@ -150,7 +150,7 @@ SHOW(__bch_cached_dev)
 {
 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
 					     disk.kobj);
-	const char *states[] = { "no cache", "clean", "dirty", "inconsistent" };
+	char const *states[] = { "no cache", "clean", "dirty", "inconsistent" };
 	int wb = dc->writeback_running;
 
 #define var(stat)		(dc->stat)