btrfs: do not check -EAGAIN when truncating inodes in the log root

We only throttle the btrfs_truncate_inode_items if the root is
SHAREABLE, which isn't set on the log root, which means this loop is
unnecessary.
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/tree-log.c

@@ -4104,13 +4104,8 @@ static int truncate_inode_items(struct btrfs_trans_handle *trans,
 		.min_type = min_type,
 		.skip_ref_updates = true,
 	};
-	int ret;
-
-	do {
-		ret = btrfs_truncate_inode_items(trans, log_root, &control);
-	} while (ret == -EAGAIN);
 
-	return ret;
+	return btrfs_truncate_inode_items(trans, log_root, &control);
 }
 
 static void fill_inode_item(struct btrfs_trans_handle *trans,