Fix test for threadpool use

Author: kpamnany

test/threadpool_use.jl

@@ -6,11 +6,6 @@ using Base.Threads
 @test nthreadpools() == 2
 @test threadpool() === :default
 @test threadpool(2) === :interactive
-dtask() = @test threadpool(current_task()) === :default
-itask() = @test threadpool(current_task()) === :interactive
-dt1 = @spawn dtask()
-dt2 = @spawn :default dtask()
-it = @spawn :interactive itask()
-wait(dt1)
-wait(dt2)
-wait(it)
+@test fetch(Threads.@spawn Threads.threadpool()) === :default
+@test fetch(Threads.@spawn :default Threads.threadpool()) === :default
+@test fetch(Threads.@spawn :interactive Threads.threadpool()) === :interactive