Clean up in vp9_rd_pick_inter_mode_sb
Clean up in vp9_rd_pick_inter_mode_sb

Use local variable.

Change-Id: I0d3df36cf4536958a0cda422f6c30da50f0e0bbf

mwgoldsmith/libvpx,ShiftMediaProject/libvpx,mbebenita/aom,ShiftMediaProject/libvpx,luctrudeau/aom,webmproject/libvpx,webmproject/libvpx,luctrudeau/aom,mwgoldsmith/vpx,smarter/aom,Topopiccione/libvpx,mwgoldsmith/libvpx,Topopiccione/libvpx,mwgoldsmith/vpx,ShiftMediaProject/libvpx,smarter/aom,mwgoldsmith/libvpx,GrokImageCompression/aom,webmproject/libvpx,smarter/aom,webmproject/libvpx,mwgoldsmith/vpx,smarter/aom,mwgoldsmith/libvpx,webmproject/libvpx,Topopiccione/libvpx,luctrudeau/aom,GrokImageCompression/aom,ittiamvpx/libvpx-1,GrokImageCompression/aom,ShiftMediaProject/libvpx,Topopiccione/libvpx,ittiamvpx/libvpx-1,Topopiccione/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,mbebenita/aom,luctrudeau/aom,mwgoldsmith/vpx,mbebenita/aom,ittiamvpx/libvpx-1,smarter/aom,luctrudeau/aom,mwgoldsmith/vpx,luctrudeau/aom,ittiamvpx/libvpx-1,mbebenita/aom,mwgoldsmith/vpx,mbebenita/aom,ittiamvpx/libvpx-1,mbebenita/aom,GrokImageCompression/aom,Topopiccione/libvpx,mbebenita/aom,ittiamvpx/libvpx-1,GrokImageCompression/aom,GrokImageCompression/aom,mwgoldsmith/libvpx,mbebenita/aom,smarter/aom,mwgoldsmith/libvpx,mbebenita/aom