message: 1. Update function names for those rewrite functions that always succeed.
  2. Remove a unused variable.
diff: @@ -337,7 +337,7 @@ absl::optional<ConvWithConvertOrClamp> FindConvWithClampAndConvertToInt8(
  return absl::nullopt;
  }
  -StatusOr<bool> TryRewriteForConvertOrClampImpl(ConvWithConvertOrClamp match) {
  +bool RewriteForConvertOrClampImpl(ConvWithConvertOrClamp match) {
  auto conv = match.conv;
  auto gte = match.gte;
  auto convert_or_clamp = match.convert_or_clamp;
  @@ -356,7 +356,7 @@ StatusOr<bool> TryRewriteForConvertOrClampImpl(ConvWithConvertOrClamp match) {
  return true;
  }
  -StatusOr<bool> TryRewriteForFinalOutput(ConvWithConvertOrClamp match) {
  +bool RewriteForFinalOutput(ConvWithConvertOrClamp match) {
  bool changed = false;
  // When the matched clamp has a single user, which is convert<int8>, we
  // will absorb it, if
  @@ -374,7 +374,7 @@ StatusOr<bool> TryRewriteForFinalOutput(ConvWithConvertOrClamp match) {
  if (match.conv->operand_count() < 4) {
  // Conv input #3 (zero based) is side_input, after x, w, and bias.
  // Side input doesn't exist in this case.
  - TF_ASSIGN_OR_RETURN(changed, TryRewriteForConvertOrClampImpl(match));
  + changed = RewriteForConvertOrClampImpl(match);
  } else if (is_one_to_one_X_to_Y_cast(match.conv->operand(3), S8, F32)) {
  // If side_input has a convert_float_to_int8, absorb it as well.
  auto side_converter = match.conv->mutable_operand(3);
  @@ -383,7 +383,7 @@ StatusOr<bool> TryRewriteForFinalOutput(ConvWithConvertOrClamp match) {
  side_converter->parent()->RemoveInstructionAndUnusedOperands(
  side_converter);
  - TF_ASSIGN_OR_RETURN(changed, TryRewriteForConvertOrClampImpl(match));
  + changed = RewriteForConvertOrClampImpl(match);
  }
  return changed;
  }
  @@ -401,11 +401,8 @@ StatusOr<bool> RunFuseClamp(HloModule* module) {
  matches.push_back(*match);
  }
  }
  - std::vector<std::pair<HloInstruction*, std::unique_ptr<HloInstruction>>>
  - replacements;
  for (const ConvWithConvertOrClamp& match : matches) {
  - TF_ASSIGN_OR_RETURN(bool c, TryRewriteForFinalOutput(match));
  - changed |= c;
  + changed |= RewriteForFinalOutput(match);
  }
  // Report error for any convolution still having int32 output.
  @@ -459,8 +456,8 @@ absl::optional<ConvWithConvertOrClamp> FindConvWithConvertToFloat(
  return absl::nullopt;
  }
  -StatusOr<bool> TryRewriteForConvertToFloat(ConvWithConvertOrClamp match) {
  - return TryRewriteForConvertOrClampImpl(match);
  +bool RewriteForConvertToFloat(ConvWithConvertOrClamp match) {
  + return RewriteForConvertOrClampImpl(match);
  }
  // Transform
  @@ -491,8 +488,7 @@ StatusOr<bool> RunFuseConvertToFloat(HloModule* module) {
  }
  for (const ConvWithConvertOrClamp& match : matches) {
  - TF_ASSIGN_OR_RETURN(bool c, TryRewriteForConvertToFloat(match));
  - changed |= c;
  + changed |= RewriteForConvertToFloat(match);
  }
  }
  return changed;
  