fix clippy lint

[alamb]

Rationale for this change

When I run clippy locally, I get the following warning. This PR fixes it.

error: redundant field names in struct initialization
   --> datafusion/src/physical_plan/hash_join.rs:392:13
    |
392 |             visited_left_side: visited_left_side,
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `visited_left_side`
    |
    = note: `-D clippy::redundant-field-names` implied by `-D warnings`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names

What changes are included in this PR?

fix clippy lint error

Are there any user-facing changes?

no

[alamb]

Also fixed in https://github.com/apache/arrow-datafusion/pull/253/files

[Dandandan]

Cool, let's merge this @alamb .

Not sure why the clippy wasn't caught by the github CI workflow?

[Dandandan]

Ah I am seeing it is explicitly allowed:

cargo clippy --all-targets --workspace -- -D warnings -A clippy::redundant_field_names

Bit weird that this is set on a global level like this, I think we should change that.