This reverts commit 3436c4bd.

This makes a leak to register dirty segments. I reproduced the issue by
modified postmark which injects a lot of file create/delete/update and
finally triggers huge number of SSR allocations.

Cc: <stable@vger.kernel.org> # v4.10+
[Jaegeuk Kim: Change missing incorrect comment]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>