tests/fate/aac: Add bitexact flags to fate-aac-pns-encode

This fixes a fate failure after bumping the minor version
Its unknown why this is not needed for the other aac tests,
more investigation needed but for now i dont want to leave
it broken while its investigated

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

tests/fate/aac.mak

@@ -169,7 +169,7 @@ fate-aac-ln-encode-128k: SIZE_TOLERANCE = 3560
 fate-aac-ln-encode-128k: FUZZ = 5
 
 FATE_AAC_ENCODE += fate-aac-pns-encode
-fate-aac-pns-encode: CMD = enc_dec_pcm adts wav s16le $(TARGET_SAMPLES)/audio-reference/luckynight_2ch_44kHz_s16.wav -strict -2 -c:a aac -aac_pns 1 -aac_is 0 -aac_ms 0 -aac_tns 0 -b:a 128k -cutoff 22050
+fate-aac-pns-encode: CMD = enc_dec_pcm adts wav s16le $(TARGET_SAMPLES)/audio-reference/luckynight_2ch_44kHz_s16.wav -strict -2 -c:a aac -aac_pns 1 -aac_is 0 -aac_ms 0 -aac_tns 0 -b:a 128k -cutoff 22050  -fflags +bitexact -flags +bitexact
 fate-aac-pns-encode: CMP = stddev
 fate-aac-pns-encode: REF = $(SAMPLES)/audio-reference/luckynight_2ch_44kHz_s16.wav
 fate-aac-pns-encode: CMP_SHIFT = -4096