Refactor prob_diff_update_savings_search_model
Refactor prob_diff_update_savings_search_model

(cherry picked from libvpx/master commit
580e815f3bb3dae7fe77327cefdfdaecc58556df)

Change-Id: Icfab58e880285d5af00985dc20db2174a67d1fe8

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