Fix a typo in a comment for ext-inter

Change-Id: I2a20b3eb8020e3e3592d284737acd5da13bad103
diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index 7001c92..3d96700 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -9195,9 +9195,9 @@
       assert(is_interintra_allowed_mode(this_mode));
 
 #if !USE_RECT_INTERINTRA
-      // Note: If the subsampling is unequal, any block size we pick
-      // either a rectangular luma block or a rectangular chroma block.
-      // So in this case, we can't use any interintra modes
+      // Note: If the subsampling is unequal, any block size we pick will
+      // result in either a rectangular luma block or a rectangular chroma
+      // block. So in this case, we can't use any interintra modes.
       if (xd->plane[1].subsampling_x != xd->plane[1].subsampling_y ||
           xd->plane[2].subsampling_x != xd->plane[2].subsampling_y)
         continue;