bcache: Fix for the build fixes

Commit 82a84eaf7e51ba3da0c36cbc401034a4e943492d left a return 0 in
closure_debug_init(). Whoops.
Signed-off-by: NKent Overstreet <koverstreet@google.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

drivers/md/bcache/closure.c

@@ -337,7 +337,6 @@ static const struct file_operations debug_ops = {
 void __init closure_debug_init(void)
 {
 	debug = debugfs_create_file("closures", 0400, NULL, NULL, &debug_ops);
-	return 0;
 }
 
 #endif