udf: fix udf_setsize() for file data in ICB

If the new size is larger than the old size and the old file data was
stored in the ICB (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) and the
new size still fits in the ICB, skip the call to udf_extend_file() as it
does not handle this i_alloc_type value (it calls BUG()).

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Jan Kara <jack@suse.cz>