Fixed typo

panda/src/grutil/geoMipTerrain.I

@@ -541,7 +541,7 @@ get_pixel_value(int x, int y) {
     return double(_heightfield.get_bright(x, y));
   } else {
     return double(_heightfield.get_red(x, y))
-         + double(_heightfield.get_green(x, y)) / 256.0;
+         + double(_heightfield.get_green(x, y)) / 256.0
          + double(_heightfield.get_blue(x, y)) / 65536.0;
   }
 }