fate: add bitexact decode flag to fate-svq3-watermark

Fixes failure with mmxext or 3dnow cpuflags enabled but ssse3 disabled
Signed-off-by: James Almer <jamrial@gmail.com>

tests/fate/qt.mak

@@ -51,7 +51,7 @@ fate-svq1-headerswap: CMD = framecrc -i $(TARGET_SAMPLES)/svq1/ct_ending_cut.mov
 
 FATE_QT-$(call ALLYES, MOV_DEMUXER SVQ3_DECODER ZLIB) += fate-svq3 fate-svq3-watermark
 fate-svq3: CMD = framecrc -i $(TARGET_SAMPLES)/svq3/Vertical400kbit.sorenson3.mov -t 6 -an
-fate-svq3-watermark: CMD = framecrc -i $(TARGET_SAMPLES)/svq3/svq3_watermark.mov
+fate-svq3-watermark: CMD = framecrc -flags +bitexact -i $(TARGET_SAMPLES)/svq3/svq3_watermark.mov
 
 FATE_QT += $(FATE_QT-yes)