Fix a bug in ransac()

For the global motion model, the number of inliers should be either 0 or
no smaller than the minimum required(3).

Change-Id: I82aa548297b1ca0a1e817ae53f26bc8cafeea77b
diff --git a/av1/encoder/ransac.c b/av1/encoder/ransac.c
index 685d93b..07e1a5f 100644
--- a/av1/encoder/ransac.c
+++ b/av1/encoder/ransac.c
@@ -530,8 +530,8 @@
       params_by_motion[i].num_inliers = motions[i].num_inliers;
       memcpy(params_by_motion[i].inliers, motions[i].inlier_indices,
              sizeof(*motions[i].inlier_indices) * npoints);
+      num_inliers_by_motion[i] = motions[i].num_inliers;
     }
-    num_inliers_by_motion[i] = motions[i].num_inliers;
   }
 
 finish_ransac: