udf: Fix extension of the last extent in the file

stable inclusion
from stable-v5.10.163
commit 6df376e245699666f9e9c2f37d6b9908dc9b925e
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7PJ9N

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6df376e245699666f9e9c2f37d6b9908dc9b925e



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[ Upstream commit 83c7423d ]

When extending the last extent in the file within the last block, we
wrongly computed the length of the last extent. This is mostly a
cosmetical problem since the extent does not contain any data and the
length will be fixed up by following operations but still.

Fixes: 1f3868f0 ("udf: Fix extending file within last block")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: zhaoxiaoqiang11 <zhaoxiaoqiang11@jd.com>