svq1dec: dont export the qscale table.

SVQ1 has no qscales so the table is of no use, and it triggers a bug as
SVQ1 does not maintain the size of the table properly causing a crash.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
