D25025: decodeBCJ2: Fix assert with broken files

[Albert Astals Cid]

aacid closed this revision.

REPOSITORY
  R243 KArchive

REVISION DETAIL
  https://phabricator.kde.org/D25025

To: aacid, apol
Cc: kde-frameworks-devel, LeGast00n, GB_2, michaelh, ngraham, bruns