avcodec/wmaprodec: Check bits per sample to be within the range not causing integer overflows

Fixes: 549d5aab1480d10f2a775ed90b0342f1/signal_sigabrt_7ffff6ae7cc9_5643_96bbb0cfe3e28be1dadfce1075016345.wma

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
