Remove dead code

This commit removes a few lines of dead code.

Change-Id: I3dfc6463cba9381ff9c7cd75cf0de8862fe525ea
diff --git a/av1/common/x86/av1_inv_txfm_avx2.c b/av1/common/x86/av1_inv_txfm_avx2.c
index 40278ea..0fbd5ea 100644
--- a/av1/common/x86/av1_inv_txfm_avx2.c
+++ b/av1/common/x86/av1_inv_txfm_avx2.c
@@ -1300,7 +1300,6 @@
   x[6] = x[1];
   x[5] = x[2];
   x[4] = x[3];
-  x[9] = x[9];
   btf_16_w16_avx2(cospi_m32_p32, cospi_p32_p32, &x[10], &x[13], _r, cos_bit);
   btf_16_w16_avx2(cospi_m32_p32, cospi_p32_p32, &x[11], &x[12], _r, cos_bit);
   idct64_stage8_high48_avx2(x, cospi, _r, cos_bit);
diff --git a/av1/common/x86/av1_inv_txfm_ssse3.c b/av1/common/x86/av1_inv_txfm_ssse3.c
index 30488ca..46c051f 100644
--- a/av1/common/x86/av1_inv_txfm_ssse3.c
+++ b/av1/common/x86/av1_inv_txfm_ssse3.c
@@ -1337,7 +1337,6 @@
   x[6] = x[1];
   x[5] = x[2];
   x[4] = x[3];
-  x[9] = x[9];
   btf_16_sse2(cospi_m32_p32, cospi_p32_p32, x[10], x[13], x[10], x[13]);
   btf_16_sse2(cospi_m32_p32, cospi_p32_p32, x[11], x[12], x[11], x[12]);
   idct64_stage8_high48_sse2(x, cospi, __rounding, cos_bit);
diff --git a/av1/common/x86/highbd_inv_txfm_avx2.c b/av1/common/x86/highbd_inv_txfm_avx2.c
index 6713da1..93e98e4 100644
--- a/av1/common/x86/highbd_inv_txfm_avx2.c
+++ b/av1/common/x86/highbd_inv_txfm_avx2.c
@@ -3273,7 +3273,6 @@
     u[6] = u[1];
     u[5] = u[2];
     u[4] = u[3];
-    u[9] = u[9];
 
     idct64_stage8_avx2(u, &cospim32, &cospi32, &cospim16, &cospi48, &cospi16,
                        &cospim48, &clamp_lo, &clamp_hi, &rnding, bit);
diff --git a/av1/common/x86/highbd_inv_txfm_sse4.c b/av1/common/x86/highbd_inv_txfm_sse4.c
index 4976d93..03eaef8 100644
--- a/av1/common/x86/highbd_inv_txfm_sse4.c
+++ b/av1/common/x86/highbd_inv_txfm_sse4.c
@@ -3576,7 +3576,6 @@
     u[6] = u[1];
     u[5] = u[2];
     u[4] = u[3];
-    u[9] = u[9];
 
     idct64_stage8_sse4_1(u, &cospim32, &cospi32, &cospim16, &cospi48, &cospi16,
                          &cospim48, &clamp_lo, &clamp_hi, &rnding, bit);