udf: Handle error when expanding directory

[ Upstream commit 33e9a53c ]

When there is an error when adding extent to the directory to expand it,
make sure to propagate the error up properly. This is not expected to
happen currently but let's make the code more futureproof.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>