Fix a build issue
Fix a build issue

When both obmc and dual_filter is enabled.

Change-Id: I56b127573a6cca31469bb357cf7a6a9c3df64071

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