mp3on4: fail when the header check fails

It seems the code assumed that when one out of multiple blocks fail
some span of time is correct, its not, its some channels
that are correct

Fixes use of uninitialized memory
Fixes: msan_uninit-mem_7f44a03ba3ce_5692_id5_1.mp4
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>