quantize: drop maxe*=gsize tonal scaling in bmask (#115)

bmask()'s tonal-masking term scaled the per-band peak energy by gsize
(the number of grouped short windows). This dates to the 2017 "initial
windows grouping support" commit, where avge changed from a single-window
average to a gsize-summed total and maxe (still a single-window peak) was
multiplied by gsize to match its scale.

The quantizer was later rewritten so the masking target uses avge/avgenrg
and maxe/avgenrg as ratios against a separately-scaled avgenrg. In that
form the gsize multiply no longer matches anything -- it just inflates the
tonal term on grouped short blocks and quantizes transients too coarsely.

Author: nschimme

libfaac/quantize.c

@@ -172,7 +172,6 @@ static void bmask(CoderInfo * __restrict coderInfo, faac_real * __restrict xr0,
     bandenrg[sfb] = avge;
     /* Track peak magnitude to identify potential Huffman overflows. */
     bandmaxe[sfb] = FAAC_SQRT(maxe);
-    maxe *= gsize;
 
     avgenrg = (totenrg / last) * (end - start);