btrfs: export __btrfs_block_rsv_release

The delalloc reserve stuff calls this directly because it cares about
the qgroup accounting stuff, so export it so we can move it around.  Fix
btrfs_block_rsv_release() to just be a static inline since it just calls
__btrfs_block_rsv_release() with NULL for the qgroup stuff.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/block-rsv.h

@@ -70,10 +70,17 @@ int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes);
 int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
 			     struct btrfs_block_rsv *dest, u64 num_bytes,
 			     int min_factor);
-void btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
-			     struct btrfs_block_rsv *block_rsv,
-			     u64 num_bytes);
 void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
 			       u64 num_bytes, bool update_size);
+u64 __btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
+			      struct btrfs_block_rsv *block_rsv,
+			      u64 num_bytes, u64 *qgroup_to_release);
+
+static inline void btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
+					   struct btrfs_block_rsv *block_rsv,
+					   u64 num_bytes)
+{
+	__btrfs_block_rsv_release(fs_info, block_rsv, num_bytes, NULL);
+}
 
 #endif /* BTRFS_BLOCK_RSV_H */

fs/btrfs/extent-tree.c

@@ -4674,7 +4674,7 @@ int btrfs_block_rsv_refill(struct btrfs_root *root,
 	return ret;
 }
 
-static u64 __btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
+u64 __btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
 			      struct btrfs_block_rsv *block_rsv,
 			      u64 num_bytes, u64 *qgroup_to_release)
 {
@@ -4692,13 +4692,6 @@ static u64 __btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
 				       qgroup_to_release);
 }
 
-void btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
-			     struct btrfs_block_rsv *block_rsv,
-			     u64 num_bytes)
-{
-	__btrfs_block_rsv_release(fs_info, block_rsv, num_bytes, NULL);
-}
-
 /**
  * btrfs_inode_rsv_release - release any excessive reservation.
  * @inode - the inode we need to release from.