tests/fate/prores: fix skip alpha tests on big endian

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

tests/fate/prores.mak

@@ -15,6 +15,6 @@ fate-prores-422_hq:    CMD = framecrc -flags +bitexact -i $(TARGET_SAMPLES)/pror
 fate-prores-422_lt:    CMD = framecrc -flags +bitexact -i $(TARGET_SAMPLES)/prores/Sequence_1-Apple_ProRes_422_LT.mov -pix_fmt yuv422p10le
 fate-prores-422_proxy: CMD = framecrc -flags +bitexact -i $(TARGET_SAMPLES)/prores/Sequence_1-Apple_ProRes_422_Proxy.mov -pix_fmt yuv422p10le
 fate-prores-alpha:     CMD = framecrc -flags +bitexact -i $(TARGET_SAMPLES)/prores/Sequence_1-Apple_ProRes_with_Alpha.mov -pix_fmt yuva444p10le
-fate-prores-alpha_skip: CMD = framecrc -flags +bitexact -skip_alpha 1 -i $(TARGET_SAMPLES)/prores/Sequence_1-Apple_ProRes_with_Alpha.mov
+fate-prores-alpha_skip: CMD = framecrc -flags +bitexact -skip_alpha 1 -i $(TARGET_SAMPLES)/prores/Sequence_1-Apple_ProRes_with_Alpha.mov -pix_fmt yuv444p10le
 fate-prores-transparency: CMD = framecrc -flags +bitexact -i $(TARGET_SAMPLES)/prores/prores4444_with_transparency.mov -pix_fmt yuva444p10le
-fate-prores-transparency_skip: CMD = framecrc -flags +bitexact -skip_alpha 1 -i $(TARGET_SAMPLES)/prores/prores4444_with_transparency.mov
+fate-prores-transparency_skip: CMD = framecrc -flags +bitexact -skip_alpha 1 -i $(TARGET_SAMPLES)/prores/prores4444_with_transparency.mov -pix_fmt yuv444p10le