LinearAlgebra: remove internal function _makevector (#55345)

It seems a bit unnecessary to have a function to carry out a `convert`,
instead of calling `convert` directly.

Author: jishnub

stdlib/LinearAlgebra/src/LinearAlgebra.jl

@@ -655,10 +655,6 @@ _evview(S::SymTridiagonal) = @view S.ev[begin:begin + length(S.dv) - 2]
 _zeros(::Type{T}, b::AbstractVector, n::Integer) where {T} = zeros(T, max(length(b), n))
 _zeros(::Type{T}, B::AbstractMatrix, n::Integer) where {T} = zeros(T, max(size(B, 1), n), size(B, 2))
 
-# convert to Vector, if necessary
-_makevector(x::Vector) = x
-_makevector(x::AbstractVector) = Vector(x)
-
 # append a zero element / drop the last element
 _pushzero(A) = (B = similar(A, length(A)+1); @inbounds B[begin:end-1] .= A; @inbounds B[end] = zero(eltype(B)); B)
 _droplast!(A) = deleteat!(A, lastindex(A))

stdlib/LinearAlgebra/src/bidiag.jl

@@ -252,8 +252,8 @@ tr(B::Bidiagonal) = sum(B.dv)
 
 function kron(A::Diagonal, B::Bidiagonal)
     # `_droplast!` is only guaranteed to work with `Vector`
-    kdv = _makevector(kron(diag(A), B.dv))
-    kev = _droplast!(_makevector(kron(diag(A), _pushzero(B.ev))))
+    kdv = convert(Vector, kron(diag(A), B.dv))
+    kev = _droplast!(convert(Vector, kron(diag(A), _pushzero(B.ev))))
     Bidiagonal(kdv, kev, B.uplo)
 end
 

stdlib/LinearAlgebra/src/diagonal.jl

@@ -684,9 +684,9 @@ function kron(A::Diagonal, B::SymTridiagonal)
 end
 function kron(A::Diagonal, B::Tridiagonal)
     # `_droplast!` is only guaranteed to work with `Vector`
-    kd = _makevector(kron(diag(A), B.d))
-    kdl = _droplast!(_makevector(kron(diag(A), _pushzero(B.dl))))
-    kdu = _droplast!(_makevector(kron(diag(A), _pushzero(B.du))))
+    kd = convert(Vector, kron(diag(A), B.d))
+    kdl = _droplast!(convert(Vector, kron(diag(A), _pushzero(B.dl))))
+    kdu = _droplast!(convert(Vector, kron(diag(A), _pushzero(B.du))))
     Tridiagonal(kdl, kd, kdu)
 end