Fix Visual Studio 2017 compilation errors.

The Visual Studio 2017 compilation errors were introduced in commit
50b2fc22d1f3814a9c863f2a8888370e65f34ff9:
https://aomedia-review.googlesource.com/c/aom/+/107364

The code compiles without error under Visual Studio 2019. I don't know
why.

1. Rempve an extra closing curly brace '}' in v128_intrinsics.h.

2. Remove 12 lines of repeated code at the end of v256_intrinsics.h.

Change-Id: I1ad45fdfbd298426b636f034dd680c051bd44bb5
diff --git a/aom_dsp/simd/v128_intrinsics.h b/aom_dsp/simd/v128_intrinsics.h
index 20808d4..218a7a6 100644
--- a/aom_dsp/simd/v128_intrinsics.h
+++ b/aom_dsp/simd/v128_intrinsics.h
@@ -78,7 +78,6 @@
 SIMD_INLINE uint32_t v128_ssd_u8_sum(c_ssd128_internal s) {
   return c_v128_ssd_u8_sum(s);
 }
-}
 SIMD_INLINE int64_t v128_dotp_su8(v128 a, v128 b) {
   return c_v128_dotp_su8(a, b);
 }
diff --git a/aom_dsp/simd/v256_intrinsics.h b/aom_dsp/simd/v256_intrinsics.h
index b66b4bb..1edbb38 100644
--- a/aom_dsp/simd/v256_intrinsics.h
+++ b/aom_dsp/simd/v256_intrinsics.h
@@ -374,16 +374,4 @@
   return c_v256_sad_u16_sum(s);
 }
 
-typedef uint32_t sad256_internal_u16;
-SIMD_INLINE sad256_internal_u16 v256_sad_u16_init(void) {
-  return c_v256_sad_u16_init();
-}
-SIMD_INLINE sad256_internal_u16 v256_sad_u16(sad256_internal_u16 s, v256 a,
-                                             v256 b) {
-  return c_v256_sad_u16(s, a, b);
-}
-SIMD_INLINE uint32_t v256_sad_u16_sum(sad256_internal_u16 s) {
-  return c_v256_sad_u16_sum(s);
-}
-
 #endif  // AOM_AOM_DSP_SIMD_V256_INTRINSICS_H_