fate/mapchan: add bitexact flag

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

tests/fate/mapchan.mak

 FATE_MAPCHAN += fate-mapchan-6ch-extract-2
 fate-mapchan-6ch-extract-2: tests/data/asynth-22050-6.wav
-fate-mapchan-6ch-extract-2: CMD = ffmpeg -i $(TARGET_PATH)/tests/data/asynth-22050-6.wav -map_channel 0.0.0 -f wav md5: -map_channel 0.0.1 -f wav md5:
+fate-mapchan-6ch-extract-2: CMD = ffmpeg -i $(TARGET_PATH)/tests/data/asynth-22050-6.wav -map_channel 0.0.0 -flags +bitexact -f wav md5: -map_channel 0.0.1 -flags +bitexact -f wav md5:
 
 FATE_MAPCHAN += fate-mapchan-6ch-extract-2-downmix-mono
 fate-mapchan-6ch-extract-2-downmix-mono: tests/data/asynth-22050-6.wav
-fate-mapchan-6ch-extract-2-downmix-mono: CMD = md5 -i $(TARGET_PATH)/tests/data/asynth-22050-6.wav -map_channel 0.0.1 -map_channel 0.0.0 -ac 1 -f wav
+fate-mapchan-6ch-extract-2-downmix-mono: CMD = md5 -i $(TARGET_PATH)/tests/data/asynth-22050-6.wav -map_channel 0.0.1 -map_channel 0.0.0 -ac 1 -flags +bitexact -f wav
 
 FATE_MAPCHAN += fate-mapchan-silent-mono
 fate-mapchan-silent-mono: tests/data/asynth-22050-1.wav
-fate-mapchan-silent-mono: CMD = md5 -i $(TARGET_PATH)/tests/data/asynth-22050-1.wav -map_channel -1 -map_channel 0.0.0 -f wav
+fate-mapchan-silent-mono: CMD = md5 -i $(TARGET_PATH)/tests/data/asynth-22050-1.wav -map_channel -1 -map_channel 0.0.0 -flags +bitexact -f wav
 
 FATE_FFMPEG += $(FATE_MAPCHAN)
 fate-mapchan: $(FATE_MAPCHAN)

tests/ref/fate/mapchan-6ch-extract-2

-40a98f34b1f34da59ff9d9ebf55654ad
-9a252de5d38890c4bf52fd1f983a1865
+6f091fe8c0be88c75921731dc9f74314
+5c2d162b9024329eb367295d37b8ca0a

tests/ref/fate/mapchan-6ch-extract-2-downmix-mono

-339a7c7c67b96df0aac636adc852a3a9
+959645ed73e6d08d8f1e947eac5d0b92

tests/ref/fate/mapchan-silent-mono

-60ebd29f1ee6b700392969083016560c
+4f5148f08587a4b9794aa52aec7852ac