[PATCH] bfq: Fix bfq linkage error

["Pavel Begunkov (Silence)" <asml.silence@xxxxxxxxx>]

From: Pavel Begunkov <asml.silence@xxxxxxxxx>

Since commit 795fe54c2a828099e ("bfq: Add per-device weight"), bfq uses
blkg_conf_prep() and blkg_conf_finish(), which are not exported. So, it
causes linkage error if bfq compiled as a module.

Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
 block/blk-cgroup.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0e2619c1a422..b6f20be0fc78 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -900,6 +900,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
 	}
 	return ret;
 }
+EXPORT_SYMBOL_GPL(blkg_conf_prep);
 
 /**
  * blkg_conf_finish - finish up per-blkg config update
@@ -915,6 +916,7 @@ void blkg_conf_finish(struct blkg_conf_ctx *ctx)
 	rcu_read_unlock();
 	put_disk_and_module(ctx->disk);
 }
+EXPORT_SYMBOL_GPL(blkg_conf_finish);
 
 static int blkcg_print_stat(struct seq_file *sf, void *v)
 {
-- 
2.22.0