Remove unnecessary caching in plan_inv of test plans

Author: gaurav-arya

Diff for: test/testplans.jl

@@ -29,15 +29,13 @@ function AbstractFFTs.plan_bfft(x::AbstractArray{T}, region; kwargs...) where {T
 end
 function AbstractFFTs.plan_inv(p::TestPlan{T}) where {T}
     unscaled_pinv = InverseTestPlan{T}(p.region, p.sz)
-    unscaled_pinv.pinv = p
     pinv = AbstractFFTs.ScaledPlan(
         unscaled_pinv, AbstractFFTs.normalization(T, p.sz, p.region),
     )
     return pinv
 end
 function AbstractFFTs.plan_inv(p::InverseTestPlan{T}) where {T}
     unscaled_pinv = TestPlan{T}(p.region, p.sz)
-    unscaled_pinv.pinv = p
     pinv = AbstractFFTs.ScaledPlan(
         unscaled_pinv, AbstractFFTs.normalization(T, p.sz, p.region),
     )
@@ -119,7 +117,6 @@ function AbstractFFTs.plan_inv(p::TestRPlan{T,N}) where {T,N}
     d = p.sz[firstdim]
     sz = ntuple(i -> i == firstdim ? d ÷ 2 + 1 : p.sz[i], Val(N))
     unscaled_pinv = InverseTestRPlan{T}(d, p.region, sz)
-    unscaled_pinv.pinv = p
     pinv = AbstractFFTs.ScaledPlan(
         unscaled_pinv, AbstractFFTs.normalization(T, p.sz, p.region),
     )
@@ -129,7 +126,6 @@ function AbstractFFTs.plan_inv(p::InverseTestRPlan{T,N}) where {T,N}
     firstdim = first(p.region)::Int
     sz = ntuple(i -> i == firstdim ? p.d : p.sz[i], Val(N))
     unscaled_pinv = TestRPlan{T}(p.region, sz)
-    unscaled_pinv.pinv = p
     pinv = AbstractFFTs.ScaledPlan(
         unscaled_pinv, AbstractFFTs.normalization(T, sz, p.region),
     )