Tune SSSE3 implementation of fast path quantization
Tune SSSE3 implementation of fast path quantization

This commit further simplifies the SSSE3 implementation of the fast
path quantization process.

Change-Id: I5be3286ec0f1bd81d1cf5be3168fece6384fb9ca

Suvarna1488/webm.libvpx,Acidburn0zzz/webm.libvpx,mbebenita/aom,GrokImageCompression/aom,shyamalschandra/libvpx,abwiz0086/webm.libvpx,ittiamvpx/libvpx,VTCSecureLLC/libvpx,reimaginemedia/webm.libvpx,kim42083/webm.libvpx,matanbs/webm.libvpx,VTCSecureLLC/libvpx,webmproject/libvpx,matanbs/webm.libvpx,liqianggao/libvpx,jmvalin/aom,altogother/webm.libvpx,ittiamvpx/libvpx,charup/https---github.com-webmproject-libvpx-,VTCSecureLLC/libvpx,stewnorriss/libvpx,n4t/libvpx,luctrudeau/aom,kalli123/webm.libvpx,matanbs/webm.libvpx,Suvarna1488/webm.libvpx,felipebetancur/libvpx,smarter/aom,matanbs/vp982,Maria1099/webm.libvpx,kalli123/webm.libvpx,Distrotech/libvpx,Acidburn0zzz/webm.libvpx,running770/libvpx,Distrotech/libvpx,luctrudeau/aom,lyx2014/libvpx_c,stewnorriss/libvpx,iniwf/webm.libvpx,jacklicn/webm.libvpx,reimaginemedia/webm.libvpx,mwgoldsmith/vpx,Distrotech/libvpx,mwgoldsmith/libvpx,Laknot/libvpx,matanbs/vp982,zofuthan/libvpx,altogother/webm.libvpx,charup/https---github.com-webmproject-libvpx-,shacklettbp/aom,abwiz0086/webm.libvpx,mwgoldsmith/vpx,ShiftMediaProject/libvpx,kleopatra999/webm.libvpx,VTCSecureLLC/libvpx,zofuthan/libvpx,matanbs/webm.libvpx,gshORTON/webm.libvpx,mbebenita/aom,mbebenita/aom,shareefalis/libvpx,kleopatra999/webm.libvpx,stewnorriss/libvpx,shareefalis/libvpx,ittiamvpx/libvpx-1,felipebetancur/libvpx,iniwf/webm.libvpx,ittiamvpx/libvpx-1,mwgoldsmith/vpx,Topopiccione/libvpx,matanbs/webm.libvpx,mbebenita/aom,mwgoldsmith/vpx,ShiftMediaProject/libvpx,GrokImageCompression/aom,altogother/webm.libvpx,felipebetancur/libvpx,Distrotech/libvpx,charup/https---github.com-webmproject-libvpx-,jacklicn/webm.libvpx,Acidburn0zzz/webm.libvpx,pcwalton/libvpx,Suvarna1488/webm.libvpx,abwiz0086/webm.libvpx,luctrudeau/aom,reimaginemedia/webm.libvpx,kim42083/webm.libvpx,Topopiccione/libvpx,smarter/aom,hsueceumd/test_hui,abwiz0086/webm.libvpx,lyx2014/libvpx_c,mwgoldsmith/vpx,goodleixiao/vpx,openpeer/libvpx_new,kalli123/webm.libvpx,jmvalin/aom,gshORTON/webm.libvpx,pcwalton/libvpx,Maria1099/webm.libvpx,matanbs/vp982,running770/libvpx,jdm/libvpx,lyx2014/libvpx_c,mwgoldsmith/libvpx,gshORTON/webm.libvpx,ittiamvpx/libvpx-1,jmvalin/aom,n4t/libvpx,running770/libvpx,shacklettbp/aom,mbebenita/aom,ittiamvpx/libvpx,mwgoldsmith/libvpx,Distrotech/libvpx,ittiamvpx/libvpx,VTCSecureLLC/libvpx,hsueceumd/test_hui,Laknot/libvpx,goodleixiao/vpx,liqianggao/libvpx,lyx2014/libvpx_c,shyamalschandra/libvpx,n4t/libvpx,openpeer/libvpx_new,GrokImageCompression/aom,hsueceumd/test_hui,jacklicn/webm.libvpx,abwiz0086/webm.libvpx,shareefalis/libvpx,Acidburn0zzz/webm.libvpx,thdav/aom,n4t/libvpx,pcwalton/libvpx,charup/https---github.com-webmproject-libvpx-,Maria1099/webm.libvpx,hsueceumd/test_hui,jdm/libvpx,smarter/aom,webmproject/libvpx,smarter/aom,liqianggao/libvpx,GrokImageCompression/aom,webmproject/libvpx,ittiamvpx/libvpx,Topopiccione/libvpx,zofuthan/libvpx,matanbs/vp982,mwgoldsmith/libvpx,smarter/aom,mbebenita/aom,kalli123/webm.libvpx,gshORTON/webm.libvpx,VTCSecureLLC/libvpx,jacklicn/webm.libvpx,shyamalschandra/libvpx,Laknot/libvpx,smarter/aom,ittiamvpx/libvpx-1,thdav/aom,Laknot/libvpx,Laknot/libvpx,ittiamvpx/libvpx-1,felipebetancur/libvpx,openpeer/libvpx_new,iniwf/webm.libvpx,kalli123/webm.libvpx,n4t/libvpx,jdm/libvpx,ittiamvpx/libvpx-1,kleopatra999/webm.libvpx,reimaginemedia/webm.libvpx,openpeer/libvpx_new,matanbs/vp982,openpeer/libvpx_new,mbebenita/aom,ShiftMediaProject/libvpx,reimaginemedia/webm.libvpx,webmproject/libvpx,shacklettbp/aom,pcwalton/libvpx,gshORTON/webm.libvpx,shacklettbp/aom,felipebetancur/libvpx,charup/https---github.com-webmproject-libvpx-,kim42083/webm.libvpx,pcwalton/libvpx,kalli123/webm.libvpx,reimaginemedia/webm.libvpx,shareefalis/libvpx,mwgoldsmith/libvpx,kim42083/webm.libvpx,shyamalschandra/libvpx,pcwalton/libvpx,webmproject/libvpx,jdm/libvpx,hsueceumd/test_hui,running770/libvpx,zofuthan/libvpx,luctrudeau/aom,Suvarna1488/webm.libvpx,stewnorriss/libvpx,shareefalis/libvpx,kleopatra999/webm.libvpx,thdav/aom,iniwf/webm.libvpx,jmvalin/aom,jacklicn/webm.libvpx,Acidburn0zzz/webm.libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,ittiamvpx/libvpx,mbebenita/aom,shacklettbp/aom,mwgoldsmith/vpx,stewnorriss/libvpx,charup/https---github.com-webmproject-libvpx-,shyamalschandra/libvpx,thdav/aom,kleopatra999/webm.libvpx,Suvarna1488/webm.libvpx,liqianggao/libvpx,luctrudeau/aom,thdav/aom,GrokImageCompression/aom,altogother/webm.libvpx,Maria1099/webm.libvpx,Acidburn0zzz/webm.libvpx,jdm/libvpx,mwgoldsmith/libvpx,thdav/aom,jmvalin/aom,abwiz0086/webm.libvpx,Maria1099/webm.libvpx,luctrudeau/aom,zofuthan/libvpx,kim42083/webm.libvpx,jdm/libvpx,shacklettbp/aom,Topopiccione/libvpx,mbebenita/aom,gshORTON/webm.libvpx,openpeer/libvpx_new,liqianggao/libvpx,matanbs/vp982,goodleixiao/vpx,running770/libvpx,matanbs/webm.libvpx,Suvarna1488/webm.libvpx,ShiftMediaProject/libvpx,altogother/webm.libvpx,goodleixiao/vpx,altogother/webm.libvpx,stewnorriss/libvpx,shyamalschandra/libvpx,lyx2014/libvpx_c,iniwf/webm.libvpx,Topopiccione/libvpx,kim42083/webm.libvpx,lyx2014/libvpx_c,liqianggao/libvpx,goodleixiao/vpx,iniwf/webm.libvpx,Topopiccione/libvpx,hsueceumd/test_hui,goodleixiao/vpx,jmvalin/aom,Distrotech/libvpx,running770/libvpx,GrokImageCompression/aom,shareefalis/libvpx,kleopatra999/webm.libvpx,zofuthan/libvpx,Maria1099/webm.libvpx,jacklicn/webm.libvpx,matanbs/vp982,felipebetancur/libvpx,Laknot/libvpx