Remove duplicated variables in EXT_INTER
Remove duplicated variables in EXT_INTER

Introduced by merge commit 141f7a9

Change-Id: Idd68e09a6cd925d97466eabebe0e4905b5031340

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