Bugfix of setting col to current integer mv's row

This CL fixed a bug which mistakenly set mv's row to col in
joint_motion_search.

For encoder, about 0.4% faster shows by encoding 20 frame
of BasketballDrill_832x480_50.y4m target 800kbps.
(138148 ms -> 137592 ms)
The coding performance changes are neutral.

   PSNR | PSNR Cb | PSNR Cr | PSNR HVS |   SSIM | MS SSIM | CIEDE 2000
-0.0029 |  0.0492 |  0.0672 |  -0.0190 | 0.0174 | -0.0131 |     0.0225

STATS_CHANGED expected

Change-Id: I7abb2013eaf00ab0e4e0634eba5bfd25aaa55941

av1/encoder/rdopt.c

diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index 997c7e9..3453afd 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -6728,7 +6728,7 @@
       } else {
         int_mv cur_int_mv, init_int_mv;
         cur_int_mv.as_mv.col = cur_mv[id].as_mv.col >> 3;
-        cur_int_mv.as_mv.row = cur_mv[id].as_mv.col >> 3;
+        cur_int_mv.as_mv.row = cur_mv[id].as_mv.row >> 3;
         init_int_mv.as_mv.row = init_mv[id].as_mv.row >> 3;
         init_int_mv.as_mv.col = init_mv[id].as_mv.col >> 3;
         if (cur_int_mv.as_int == init_int_mv.as_int) {