Fix hard-coded block size in `temporal_filter.c`.

Use the passed-in argument to replace the harded-coded one in function
`tf_motion_search()`.

Change-Id: I4bf7bb71509ad7cee1966ee8e3c7bdcf91c5179e

av1/encoder/temporal_filter.c

diff --git a/av1/encoder/temporal_filter.c b/av1/encoder/temporal_filter.c
index 7e2c286..1115d4a 100644
--- a/av1/encoder/temporal_filter.c
+++ b/av1/encoder/temporal_filter.c
@@ -150,7 +150,7 @@
     mb->e_mbd.mi[0]->mv[0] = mb->best_mv;
     *ref_mv = mb->best_mv.as_mv;
     // On 4 sub-blocks.
-    const BLOCK_SIZE subblock_size = ss_size_lookup[BLOCK_32X32][1][1];
+    const BLOCK_SIZE subblock_size = ss_size_lookup[block_size][1][1];
     const int subblock_height = block_size_high[subblock_size];
     const int subblock_width = block_size_wide[subblock_size];
     start_mv.row = GET_MV_RAWPEL(ref_mv->row);