ReconstructRow: move some one-time inits out of the main loop
ReconstructRow: move some one-time inits out of the main loop

+ some cosmetics clean-up

Change-Id: Ifb34b914844bb7734137bacd61fcfc4a13971665

Suvarna1488/webm.libwebp,kalli123/webm.libwebp,abwiz0086/webm.libwebp,zofuthan/libwebp,jiehu5114/libwebp,rxl194/libwebp,PKRoma/libwebp,ttyangf/libwebp,gshORTON/webm.libwebp,rxl194/libwebp,imazen/libwebp,PKRoma/libwebp,Aexyn/libwebp,redengineer/libwebp,ya7lelkom/libwebp,redengineer/libwebp,zofuthan/libwebp,Suvarna1488/webm.libwebp,rxl194/libwebp,webmproject/libwebp,PKRoma/libwebp,kalli123/webm.libwebp,imazen/libwebp,PKRoma/libwebp,Aexyn/libwebp,gshORTON/webm.libwebp,abwiz0086/webm.libwebp,PKRoma/libwebp,yohunl/libwebp,imazen/libwebp,kalli123/webm.libwebp,abwiz0086/webm.libwebp,gshORTON/webm.libwebp,Aexyn/libwebp,zofuthan/libwebp,Suvarna1488/webm.libwebp,jiehu5114/libwebp,ttyangf/libwebp,redengineer/libwebp,PKRoma/libwebp,webmproject/libwebp,jiehu5114/libwebp,ya7lelkom/libwebp,yohunl/libwebp,ya7lelkom/libwebp,gshORTON/webm.libwebp,Suvarna1488/webm.libwebp,webmproject/libwebp,jacklicn/libwebp,Aexyn/libwebp,redengineer/libwebp,zofuthan/libwebp,ya7lelkom/libwebp,Suvarna1488/webm.libwebp,Aexyn/libwebp,webmproject/libwebp,zofuthan/libwebp,jacklicn/libwebp,webmproject/libwebp,rxl194/libwebp,redengineer/libwebp,yohunl/libwebp,imazen/libwebp,imazen/libwebp,rxl194/libwebp,ttyangf/libwebp,yohunl/libwebp,yohunl/libwebp,ttyangf/libwebp,kalli123/webm.libwebp,jacklicn/libwebp,abwiz0086/webm.libwebp,ttyangf/libwebp,jacklicn/libwebp,abwiz0086/webm.libwebp,gshORTON/webm.libwebp,ya7lelkom/libwebp,kalli123/webm.libwebp,jacklicn/libwebp,jiehu5114/libwebp,jiehu5114/libwebp