What type of PR is this?
/kind bug
/kind task

What does this PR do / why do we need it:
If the u1 only used by Load and one other updatestate, no need to replace.

// Replace UpdateStates with U for first load.
// Covert:
// u1 = UpdateState(u, c)
// p1 = Load(para1, u1) // first load for para1, it maybe replace by the first monad in graph or new monad
// u2 = UpdateState(u1, p1)
// To:
// u1 = UpdateState(u, c)
// p1 = Load(para1, u1) // u1 no need to replace.
// u2 = UpdateState(u1, p1)

Which issue(s) this PR fixes:
Fixes #
fix the stochastic accuracy problem in GPU:
test_032_for_in_for.py::test_for_in_for_02

Special notes for your reviewers: