libavcodec/motion-test: set the bitexact flag

this is needed for testing mmx2 functions

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
motion-test: fix warning: dsp_mask is deprecated

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ac3enc_template: silence may be used uninitialized in this function warnings

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