simplify gpu code

Author: ChrisRackauckas

ext/LinearSolveCUDAExt.jl

@@ -17,13 +17,6 @@ function SciMLBase.solve!(cache::LinearSolve.LinearCache, alg::CudaOffloadFactor
 end
 
 function LinearSolve.do_factorization(alg::CudaOffloadFactorization, A, b, u)
-    A isa Union{AbstractMatrix, AbstractSciMLOperator} ||
-        error("LU is not defined for $(typeof(A))")
-
-    if A isa Union{MatrixOperator, DiffEqArrayOperator}
-        A = A.A
-    end
-
     fact = lu(CUDA.CuArray(A))
     return fact
 end