notes, lint.

Author: trivialfis

src/common/linalg_op.h

@@ -99,7 +99,6 @@ void ElementWiseKernel(linalg::TensorView<T, D> t, std::int32_t n_threads, Fn&&
 }
 }  // namespace cpu_impl
 
-
 template <typename T, std::int32_t kDim>
 auto cbegin(TensorView<T, kDim> const& v) {  // NOLINT
   auto it = common::MakeIndexTransformIter([&](std::size_t i) -> std::remove_cv_t<T> const& {
@@ -125,7 +124,9 @@ auto end(TensorView<T, kDim>& v) {  // NOLINT
   return begin(v) + v.Size();
 }
 
-// A tag to workaround the one definition rule.
+// A tag to workaround the one definition rule. Anything that can function differently in
+// two different TUs without change of function signiture can violate this rule. The tag
+// is used to create a new function signiture accordingly.
 template <bool kWithCuda, bool kWithSycl>
 struct SysTagImpl {};
 
@@ -226,7 +227,8 @@ void TransformKernel(Context const* ctx, TensorView<T, D> t, Fn&& fn, SysTag = S
 }
 
 // vector-scalar multiplication
-inline void VecScaMul(Context const* ctx, linalg::VectorView<float> x, double mul, SysTag = SysTag{}) {
+inline void VecScaMul(Context const* ctx, linalg::VectorView<float> x, double mul,
+                      SysTag = SysTag{}) {
   CHECK_EQ(x.Device().ordinal, ctx->Device().ordinal);
   TransformKernel(ctx, x, [=] XGBOOST_DEVICE(float v) { return v * mul; });
 }