ensure that seek_test is rebuild if any of the libs changed

Originally committed as revision 8788 to svn://svn.ffmpeg.org/ffmpeg/trunk

tests/Makefile

@@ -82,8 +82,10 @@ audiogen$(EXESUF): audiogen.c
 tiny_psnr$(EXESUF): tiny_psnr.c
 	$(CC) $(LDFLAGS) $(CFLAGS) -o $@ $<
 
+LIBAV = ../libavformat/libavformat.a ../libavcodec/libavcodec.a ../libavutil/libavutil.a
+
 #FIXME cleanup shit below
-seek_test$(EXESUF): seek_test.c
+seek_test$(EXESUF): seek_test.c $(LIBAV)
 	$(CC) $(LDFLAGS) $(CFLAGS) -DHAVE_AV_CONFIG_H -I.. -I$(SRC_PATH)/libavformat/ -I$(SRC_PATH)/libavcodec/ -I$(SRC_PATH)/libavutil/ -o $@ $< $(SRC_PATH)/libavformat/libavformat.a $(SRC_PATH)/libavcodec/libavcodec.a $(SRC_PATH)/libavutil/libavutil.a $(EXTRALIBS)
 
 DSPDEPS = $(SRC_PATH)/libavcodec/i386/dsputil_mmx.c \