### What changes were proposed in this pull request?
`CurrentOrigin` is a thread-local variable to track the original SQL line position in plan/expression. Usually, we set `CurrentOrigin`, create `TreeNode` instances, and reset `CurrentOrigin`.
This PR updates the last step to set `CurrentOrigin` to its previous value, instead of resetting it. This is necessary when we invoke `CurrentOrigin` in a nested way, like with subqueries.
### Why are the changes needed?
To keep the original SQL line position in the error message in more cases.
### Does this PR introduce _any_ user-facing change?
No, only minor error message changes.
### How was this patch tested?
existing tests
Closes#32249 from cloud-fan/origin.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
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