avcodec/ac3: always use hardcoded tables

The table in question is a 253 byte one. In fact, it turns out that
dynamic generation of the table results in an increased binary size.

Code compiled with GCC 5.2.0, x86-64 (size in bytes), before and after
patch:
old: 62321064 libavcodec/libavcodec.so.57
new: 62320536 libavcodec/libavcodec.so.57

Thus, it always make sense to statically allocate this.

Tested with FATE with/without --enable-hardcoded-tables.

Reviewed-by: wm4 <nfxjfg@googlemail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

libavcodec/ac3dec.c

@@ -185,7 +185,6 @@ static av_cold int ac3_decode_init(AVCodecContext *avctx)
 
     s->avctx = avctx;
 
-    ff_ac3_common_init();
     ac3_tables_init();
     ff_mdct_init(&s->imdct_256, 8, 1, 1.0);
     ff_mdct_init(&s->imdct_512, 9, 1, 1.0);