fate/colorkey: disable audio stream.

The test is not supposed to cover audio.
Also, using -vframes along with an audio stream depends on
the exact order the frames are processed by filters, it is
too much constraint to guarantee.

tests/fate/ffmpeg.mak

@@ -20,7 +20,7 @@ fate-ffmpeg-filter_complex: CMD = framecrc -filter_complex color=d=1:r=5 -fflags
 
 FATE_SAMPLES_FFMPEG-$(CONFIG_COLORKEY_FILTER) += fate-ffmpeg-filter_colorkey
 fate-ffmpeg-filter_colorkey: tests/data/filtergraphs/colorkey
-fate-ffmpeg-filter_colorkey: CMD = framecrc -idct simple -fflags +bitexact -flags +bitexact  -sws_flags +accurate_rnd+bitexact -i $(TARGET_SAMPLES)/cavs/cavs.mpg -fflags +bitexact -flags +bitexact -sws_flags +accurate_rnd+bitexact -i $(TARGET_SAMPLES)/lena.pnm -filter_complex_script $(TARGET_PATH)/tests/data/filtergraphs/colorkey -sws_flags +accurate_rnd+bitexact -fflags +bitexact -flags +bitexact -qscale 2 -vframes 10
+fate-ffmpeg-filter_colorkey: CMD = framecrc -idct simple -fflags +bitexact -flags +bitexact  -sws_flags +accurate_rnd+bitexact -i $(TARGET_SAMPLES)/cavs/cavs.mpg -fflags +bitexact -flags +bitexact -sws_flags +accurate_rnd+bitexact -i $(TARGET_SAMPLES)/lena.pnm -an -filter_complex_script $(TARGET_PATH)/tests/data/filtergraphs/colorkey -sws_flags +accurate_rnd+bitexact -fflags +bitexact -flags +bitexact -qscale 2 -vframes 10
 
 FATE_FFMPEG-$(CONFIG_COLOR_FILTER) += fate-ffmpeg-lavfi
 fate-ffmpeg-lavfi: CMD = framecrc -lavfi color=d=1:r=5 -fflags +bitexact

tests/ref/fate/ffmpeg-filter_colorkey

@@ -3,18 +3,8 @@
 #codec_id 0: rawvideo
 #dimensions 0: 720x576
 #sar 0: 0/1
-#tb 1: 1/48000
-#media_type 1: audio
-#codec_id 1: pcm_s16le
-#sample_rate 1: 48000
-#channel_layout 1: 3
-#channel_layout_name 1: stereo
 0,          0,          0,        1,   622080, 0x4e30accb
-1,          0,          0,     1152,     4608, 0x00000000
-1,       1152,       1152,     1152,     4608, 0xbca29063
 0,          1,          1,        1,   622080, 0x7d941c14
-1,       2304,       2304,     1152,     4608, 0x6e70df10
-1,       3456,       3456,     1152,     4608, 0x95e6a535
 0,          2,          2,        1,   622080, 0xf7451c5b
 0,          3,          3,        1,   622080, 0xb2c74319
 0,          4,          4,        1,   622080, 0xc9b80b79