Merge commit '3aa9d37d'

* commit '3aa9d37d':
  build: Fix directory dependencies of tests/pixfmts.mak target

This might not be necessary given our mkdirs in the configure, but it
probably doesn't hurt.

Merged-by: Clément Bœsch <u@pkh.me>

tests/fate/filter-video.mak

@@ -538,7 +538,7 @@ fate-filter-tile: CMD = video_filter "tile=3x3:nb_frames=5:padding=7:margin=2"
 
 
 tests/pixfmts.mak: TAG = GEN
-tests/pixfmts.mak: ffmpeg$(PROGSSUF)$(EXESUF)
+tests/pixfmts.mak: ffmpeg$(PROGSSUF)$(EXESUF) | tests
 	$(M)printf "PIXFMTS = " > $@
 	$(Q)$(TARGET_EXEC) $(TARGET_PATH)/$< -pix_fmts list 2> /dev/null | awk 'NR > 8 && /^IO/ { printf $$2 " " }' >> $@
 	$(Q)printf "\n" >> $@