btrfs: stop passing root argument to btrfs_add_delalloc_inodes()

There's no need to pass a root argument to btrfs_add_delalloc_inodes(), we
can just pass the inode since the root is always the root associated to
the inode in the context it's called. So remove it and have the single
caller pass only the inode.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -2385,10 +2385,10 @@ void btrfs_merge_delalloc_extent(struct btrfs_inode *inode, struct extent_state
 	spin_unlock(&inode->lock);
 }
 
-static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
-				      struct btrfs_inode *inode)
+static void btrfs_add_delalloc_inodes(struct btrfs_inode *inode)
 {
-	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	struct btrfs_root *root = inode->root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
 
 	spin_lock(&root->delalloc_lock);
 	if (list_empty(&inode->delalloc_inodes)) {
@@ -2451,7 +2451,6 @@ void btrfs_set_delalloc_extent(struct btrfs_inode *inode, struct extent_state *s
 	 * bit, which is only set or cleared with irqs on
 	 */
 	if (!(state->state & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
-		struct btrfs_root *root = inode->root;
 		u64 len = state->end + 1 - state->start;
 		u32 num_extents = count_max_extents(fs_info, len);
 		bool do_list = !btrfs_is_free_space_inode(inode);
@@ -2472,7 +2471,7 @@ void btrfs_set_delalloc_extent(struct btrfs_inode *inode, struct extent_state *s
 			inode->defrag_bytes += len;
 		if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
 					 &inode->runtime_flags))
-			btrfs_add_delalloc_inodes(root, inode);
+			btrfs_add_delalloc_inodes(inode);
 		spin_unlock(&inode->lock);
 	}