avcodec/diracdec: Fix "warning: comparison of constant 4 with expression of type enum dirac_subband is always true [-Wtautological-constant-out-of-range-compare]"

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/cabac_functions: fix "warning: UNCHECKED_BITSTREAM_READER is not defined, evaluates to 0"

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>