fix calculate in many_to_many_hash_partition test.

[Ted-Jiang]

Which issue does this PR close?

#1462

Closes #.

[Dandandan]

@Ted-Jiang great find/fix! there is one clippy error:

   --> datafusion/src/physical_plan/repartition.rs:581:24
    |
581 |             .map(|x| x.into_iter().map(|x| x.num_rows()).sum::<usize>())
    |                        ^^^^^^^^^ help: call directly: `iter`
    |
    = note: `-D clippy::into-iter-on-ref` implied by `-D warnings`

[Ted-Jiang]

@Ted-Jiang great find/fix! there is one clippy error:

   --> datafusion/src/physical_plan/repartition.rs:581:24
    |
581 |             .map(|x| x.into_iter().map(|x| x.num_rows()).sum::<usize>())
    |                        ^^^^^^^^^ help: call directly: `iter`
    |
    = note: `-D clippy::into-iter-on-ref` implied by `-D warnings`

Thanks, how do i check this before commit ? i can not find in Developer's guide 😂

[Dandandan]

@Ted-Jiang great find/fix! there is one clippy error:

   --> datafusion/src/physical_plan/repartition.rs:581:24
    |
581 |             .map(|x| x.into_iter().map(|x| x.num_rows()).sum::<usize>())
    |                        ^^^^^^^^^ help: call directly: `iter`
    |
    = note: `-D clippy::into-iter-on-ref` implied by `-D warnings`

Thanks, how do i check this before commit ? i can not find in Developer's guide 😂

You can run cargo clippy

@Ted-Jiang great find/fix! there is one clippy error:

   --> datafusion/src/physical_plan/repartition.rs:581:24
    |
581 |             .map(|x| x.into_iter().map(|x| x.num_rows()).sum::<usize>())
    |                        ^^^^^^^^^ help: call directly: `iter`
    |
    = note: `-D clippy::into-iter-on-ref` implied by `-D warnings`

Thanks, how do i check this before commit ? i can not find in Developer's guide 😂

You can run cargo clippy and you get the warnings 👍

[Dandandan]

Thank you @Ted-Jiang