[PATCH] btrfs: make unpin_extent_cache return void

[baomingtong001@208suo.com]

The return value of unpin_extent_cache is always 0,
and its caller does not check its return value.

Signed-off-by: Mingtong Bao <baomingtong001@208suo.com>
---
  fs/btrfs/extent_map.c | 3 +--
  fs/btrfs/extent_map.h | 2 +-
  2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index f3e9aaeb9956..845994b47998 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -292,7 +292,7 @@ static void try_merge_map(struct extent_map_tree 
*tree, struct extent_map *em)
   * to the generation that actually added the file item to the inode so 
we know
   * we need to sync this extent when we call fsync().
   */
-int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 
len,
+void unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 
len,
                 u64 gen)
  {
      struct extent_map *em;
@@ -326,7 +326,6 @@ int unpin_extent_cache(struct extent_map_tree *tree, 
u64 start, u64 len,
      free_extent_map(em);
  out:
      write_unlock(&tree->lock);
-    return 0;

  }

diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index 35d27c756e08..486a8ea798c7 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -97,7 +97,7 @@ struct extent_map *alloc_extent_map(void);
  void free_extent_map(struct extent_map *em);
  int __init extent_map_init(void);
  void __cold extent_map_exit(void);
-int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 
len, u64 gen);
+void unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 
len, u64 gen);
  void clear_em_logging(struct extent_map_tree *tree, struct extent_map 
*em);
  struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
                       u64 start, u64 len);