avfilter: Compile FIFO filters unconditionally

Building libavfilter without that functionality makes little sense.

libavfilter/Makefile

@@ -19,11 +19,11 @@ OBJS = allfilters.o                                                     \
        buffersink.o                                                     \
        buffersrc.o                                                      \
        drawutils.o                                                      \
+       fifo.o                                                           \
        formats.o                                                        \
        graphparser.o                                                    \
        video.o                                                          \
 
-OBJS-$(CONFIG_AFIFO_FILTER)                  += fifo.o
 OBJS-$(CONFIG_AFORMAT_FILTER)                += af_aformat.o
 OBJS-$(CONFIG_AMIX_FILTER)                   += af_amix.o
 OBJS-$(CONFIG_ANULL_FILTER)                  += af_anull.o
@@ -50,7 +50,6 @@ OBJS-$(CONFIG_DRAWBOX_FILTER)                += vf_drawbox.o
 OBJS-$(CONFIG_DRAWTEXT_FILTER)               += vf_drawtext.o
 OBJS-$(CONFIG_FADE_FILTER)                   += vf_fade.o
 OBJS-$(CONFIG_FIELDORDER_FILTER)             += vf_fieldorder.o
-OBJS-$(CONFIG_FIFO_FILTER)                   += fifo.o
 OBJS-$(CONFIG_FORMAT_FILTER)                 += vf_format.o
 OBJS-$(CONFIG_FPS_FILTER)                    += vf_fps.o
 OBJS-$(CONFIG_FREI0R_FILTER)                 += vf_frei0r.o

libavfilter/allfilters.c

@@ -35,7 +35,6 @@ void avfilter_register_all(void)
         return;
     initialized = 1;
 
-    REGISTER_FILTER (AFIFO,       afifo,       af);
     REGISTER_FILTER (AFORMAT,     aformat,     af);
     REGISTER_FILTER (AMIX,        amix,        af);
     REGISTER_FILTER (ANULL,       anull,       af);
@@ -62,7 +61,6 @@ void avfilter_register_all(void)
     REGISTER_FILTER (DRAWTEXT,    drawtext,    vf);
     REGISTER_FILTER (FADE,        fade,        vf);
     REGISTER_FILTER (FIELDORDER,  fieldorder,  vf);
-    REGISTER_FILTER (FIFO,        fifo,        vf);
     REGISTER_FILTER (FORMAT,      format,      vf);
     REGISTER_FILTER (FPS,         fps,         vf);
     REGISTER_FILTER (FREI0R,      frei0r,      vf);
@@ -119,4 +117,12 @@ void avfilter_register_all(void)
         extern AVFilter avfilter_asink_abuffer;
         avfilter_register(&avfilter_asink_abuffer);
     }
+    {
+        extern AVFilter avfilter_af_afifo;
+        avfilter_register(&avfilter_af_afifo);
+    }
+    {
+        extern AVFilter avfilter_vf_fifo;
+        avfilter_register(&avfilter_vf_fifo);
+    }
 }