btrfs: opencode extent_buffer_get

The helper is trivial and we can understand what the atomic_inc on
something named refs does.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index fde0973..f414fd9 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1811,7 +1811,7 @@ static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
 		btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
 
 	/* For src_path */
-	extent_buffer_get(src_eb);
+	atomic_inc(&src_eb->refs);
 	src_path->nodes[root_level] = src_eb;
 	src_path->slots[root_level] = dst_path->slots[root_level];
 	src_path->locks[root_level] = 0;
@@ -2067,7 +2067,7 @@ static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
 		goto out;
 	}
 	/* For dst_path */
-	extent_buffer_get(dst_eb);
+	atomic_inc(&dst_eb->refs);
 	dst_path->nodes[level] = dst_eb;
 	dst_path->slots[level] = 0;
 	dst_path->locks[level] = 0;
@@ -2126,7 +2126,7 @@ int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
 	 * walk back up the tree (adjusting slot pointers as we go)
 	 * and restart the search process.
 	 */
-	extent_buffer_get(root_eb); /* For path */
+	atomic_inc(&root_eb->refs);	/* For path */
 	path->nodes[root_level] = root_eb;
 	path->slots[root_level] = 0;
 	path->locks[root_level] = 0; /* so release_path doesn't try to unlock */