udf: Handle error when expanding directory

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>

fs/udf/namei.c

@@ -192,8 +192,13 @@ static struct buffer_head *udf_expand_dir_adinicb(struct inode *inode,
 	epos.bh = NULL;
 	epos.block = iinfo->i_location;
 	epos.offset = udf_file_entry_alloc_offset(inode);
-	udf_add_aext(inode, &epos, &eloc, inode->i_size, 0);
+	ret = udf_add_aext(inode, &epos, &eloc, inode->i_size, 0);
 	brelse(epos.bh);
+	if (ret < 0) {
+		*err = ret;
+		udf_free_blocks(inode->i_sb, inode, &eloc, 0, 1);
+		return NULL;
+	}
 	mark_inode_dirty(inode);
 
 	/* Now fixup tags in moved directory entries */