Fix compile error of VAR_TX in rdopt.c
Fix compile error of VAR_TX in rdopt.c

Change-Id: Ibb2e2768917fd0cbcee42fc31c3bea1909e626d3

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