jbd2: if the journal is aborted then don't allow update of the log tail

[ Upstream commit 85e0c4e8 ]

This updates the jbd2 superblock unnecessarily, and on an abort we
shouldn't truncate the log.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>