bcache: Move couple of string arrays to sysfs.c

There is couple of string arrays that are used exclusively in sysfs.c.
Move it to there and make them static.

Besides above, it will allow further clean up.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/bcache/sysfs.c

@@ -16,6 +16,24 @@
 #include <linux/sort.h>
 #include <linux/sched/clock.h>
 
+/* Default is -1; we skip past it for struct cached_dev's cache mode */
+static const char * const bch_cache_modes[] = {
+	"default",
+	"writethrough",
+	"writeback",
+	"writearound",
+	"none",
+	NULL
+};
+
+/* Default is -1; we skip past it for stop_when_cache_set_failed */
+static const char * const bch_stop_on_failure_modes[] = {
+	"default",
+	"auto",
+	"always",
+	NULL
+};
+
 static const char * const cache_replacement_policies[] = {
 	"lru",
 	"fifo",