Zero segment counter before accumulating.
Zero segment counter before accumulating.

The segment counts are computed as part of packing the bitstream,
so they might have been computed already in the recode loop. Zero
the accumulator to avoid double counting.

This fixes some encoder/decoder mismatches.

Change-Id: Ib7816034cbbb1db41101116b706302b02fad3a2c

smarter/aom,smarter/aom,mbebenita/aom,smarter/aom,smarter/aom,mbebenita/aom,luctrudeau/aom,mbebenita/aom,GrokImageCompression/aom,luctrudeau/aom,mbebenita/aom,GrokImageCompression/aom,luctrudeau/aom,GrokImageCompression/aom,smarter/aom,luctrudeau/aom,GrokImageCompression/aom,mbebenita/aom,mbebenita/aom,GrokImageCompression/aom,mbebenita/aom,luctrudeau/aom,smarter/aom,luctrudeau/aom,GrokImageCompression/aom,mbebenita/aom,mbebenita/aom