MINOR: Fix clippy for rust 1.64.0

[viirya]

Which issue does this PR close?

Rationale for this change

Fixing four clippy errors for rust 1.64.0 in CI:

error: unused return value of `std::boxed::Box::<T>::from_raw` that must be used
    --> arrow/src/ffi.rs:1395:13
     |
1395 |             Box::from_raw(out_array_ptr);
     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = note: `-D unused-must-use` implied by `-D warnings`
     = note: call `drop(from_raw(ptr))` if you intend to drop the `Box`

error: unused return value of `std::boxed::Box::<T>::from_raw` that must be used
    --> arrow/src/ffi.rs:1396:13
     |
1396 |             Box::from_raw(out_schema_ptr);
     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = note: call `drop(from_raw(ptr))` if you intend to drop the `Box`

error: this expression borrows a value the compiler would automatically borrow
    --> parquet/src/column/writer/mod.rs:1074:13
     |
1074 |             (&a[0..lead_length]).iter().any(|&x| x != extension)
     |             ^^^^^^^^^^^^^^^^^^^^ help: change this to: `a[0..lead_length]`
     |
     = note: `-D clippy::needless-borrow` implied by `-D warnings`
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

error: this expression borrows a value the compiler would automatically borrow
    --> parquet/src/column/writer/mod.rs:1077:13
     |
1077 |             (&b[0..lead_length]).iter().any(|&x| x != extension)
     |             ^^^^^^^^^^^^^^^^^^^^ help: change this to: `b[0..lead_length]`
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

What changes are included in this PR?

Are there any user-facing changes?

[viirya]

@sunchao Missed another four clippy errors.

[viirya]

Thanks.

[ursabot]

Benchmark runs are scheduled for baseline = c2972c1 and contender = b7bcfd8. b7bcfd8 is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on ec2-t3-xlarge-us-east-2] ec2-t3-xlarge-us-east-2
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on test-mac-arm] test-mac-arm
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on ursa-i9-9960x] ursa-i9-9960x
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on ursa-thinkcentre-m75q] ursa-thinkcentre-m75q
Buildkite builds:
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java