ac3enc: fix LOCAL_ALIGNED usage in count_mantissa_bits()

Signed-off-by: Mans Rullgard <mans@mansr.com>

libavcodec/ac3enc.c

@@ -1519,7 +1519,7 @@ static void count_mantissa_bits_update_ch(AC3EncodeContext *s, int ch,
 static int count_mantissa_bits(AC3EncodeContext *s)
 {
     int ch, max_end_freq;
-    LOCAL_ALIGNED_16(uint16_t, mant_cnt,[AC3_MAX_BLOCKS][16]);
+    LOCAL_ALIGNED_16(uint16_t, mant_cnt, [AC3_MAX_BLOCKS], [16]);
 
     count_mantissa_bits_init(mant_cnt);