fate: remove redundant aref and vref references

The ref targets are included in the FATE_[AV]CODEC lists created
by configure so they do not need to be listed separately in the
makefile.  Filter them out when setting dependencies to avoid make
warnings about circular deps.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Makefile

@@ -194,10 +194,6 @@ REFS = $(AREF) $(VREF)
 $(VREF): ffmpeg$(EXESUF) tests/vsynth1/00.pgm tests/vsynth2/00.pgm
 $(AREF): ffmpeg$(EXESUF) tests/data/asynth1.sw
 
-fate-acodec-aref:  CMD = codectest acodec
-fate-vsynth1-vref: CMD = codectest vsynth1
-fate-vsynth2-vref: CMD = codectest vsynth2
-
 ffservertest: ffserver$(EXESUF) tests/vsynth1/00.pgm tests/data/asynth1.sw
 	@echo
 	@echo "Unfortunately ffserver is broken and therefore its regression"
@@ -250,8 +246,8 @@ FATE = $(FATE_ACODEC)                                                   \
        $(FATE_LAVFI)                                                    \
        $(FATE_SEEK)                                                     \
 
-$(FATE_ACODEC): $(AREF)
-$(FATE_VCODEC): $(VREF)
+$(filter-out %-aref,$(FATE_ACODEC)): $(AREF)
+$(filter-out %-vref,$(FATE_VCODEC)): $(VREF)
 $(FATE_LAVF):   $(REFS)
 $(FATE_LAVFI):  $(REFS) tools/lavfi-showfiltfmts$(EXESUF)
 $(FATE_SEEK):   fate-codec fate-lavf tests/seek_test$(EXESUF)
@@ -285,7 +281,7 @@ FATE_UTILS = base64 tiny_psnr
 
 fate: $(FATE)
 
-$(FATE) $(REFS): ffmpeg$(EXESUF) $(FATE_UTILS:%=tests/%$(HOSTEXESUF))
+$(FATE): ffmpeg$(EXESUF) $(FATE_UTILS:%=tests/%$(HOSTEXESUF))
 	@echo "TEST    $(@:fate-%=%)"
 	$(Q)$(SRC_PATH)/tests/fate-run.sh $@ "$(SAMPLES)" "$(TARGET_EXEC)" "$(TARGET_PATH)" '$(CMD)' '$(CMP)' '$(REF)' '$(FUZZ)' '$(THREADS)' '$(THREAD_TYPE)'