Some cosmetic renaming for consistency

Change-Id: I083bb9fa7a861eb0b37405166393ff0daca5589d
diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index ef259af..f516e8b 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -3170,8 +3170,8 @@
       fix_interp_filter(cm, cpi->td.counts);
       write_frame_interp_filter(cm->interp_filter, wb);
       aom_wb_write_bit(wb, cm->switchable_motion_mode);
-      if (frame_might_use_prev_frame_mvs(cm)) {
-        aom_wb_write_bit(wb, cm->use_ref_frame_mvs);
+      if (frame_might_allow_ref_frame_mvs(cm)) {
+        aom_wb_write_bit(wb, cm->allow_ref_frame_mvs);
       }
     }
   }
@@ -3252,7 +3252,7 @@
 
   if (cm->is_skip_mode_allowed) aom_wb_write_bit(wb, cm->skip_mode_flag);
 
-  if (frame_might_use_warped_motion(cm))
+  if (frame_might_allow_warped_motion(cm))
     aom_wb_write_bit(wb, cm->allow_warped_motion);
   else
     assert(!cm->allow_warped_motion);