Fix a typo bug in apply_temporal_filter_planewise

In apply_temporal_filter_planewise(), change
      if (row <= block_width - 4) {
to
      if (row <= block_height - 4) {

On the master branch, this typo bug was fixed as part of
commit f4043caf9ef420046a903433f0a8e24aca019a4f.

BUG=aomedia:2903

Change-Id: Iecf473f256aabd395e3d77f61d1b5439c86d24aa
diff --git a/av1/encoder/x86/temporal_filter_avx2.c b/av1/encoder/x86/temporal_filter_avx2.c
index 1baf032..847f728 100644
--- a/av1/encoder/x86/temporal_filter_avx2.c
+++ b/av1/encoder/x86/temporal_filter_avx2.c
@@ -184,7 +184,7 @@
       }
 
       // Load next row to the last element
-      if (row <= block_width - 4) {
+      if (row <= block_height - 4) {
         vsrc[4] = xx_load_and_pad(src, col, block_width);
         src += SSE_STRIDE;
       } else {