bcache: prefer 'help' in Kconfig

Current bcache Kconfig uses '---help---' as header of help information,
for now 'help' is prefered. This patch fixes this style by replacing
'---help---' by 'help' in bcache Kconfig file.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NShenghui Wang <shhuiw@foxmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

drivers/md/bcache/Kconfig

 
 config BCACHE
 	tristate "Block device as cache"
-	---help---
+	help
 	Allows a block device to be used as cache for other devices; uses
 	a btree for indexing and the layout is optimized for SSDs.
 
@@ -10,7 +10,7 @@ config BCACHE
 config BCACHE_DEBUG
 	bool "Bcache debugging"
 	depends on BCACHE
-	---help---
+	help
 	Don't select this option unless you're a developer
 
 	Enables extra debugging tools, allows expensive runtime checks to be
@@ -20,7 +20,7 @@ config BCACHE_CLOSURES_DEBUG
 	bool "Debug closures"
 	depends on BCACHE
 	select DEBUG_FS
-	---help---
+	help
 	Keeps all active closures in a linked list and provides a debugfs
 	interface to list them, which makes it possible to see asynchronous
 	operations that get stuck.