fix: use libc::O_DIRECT for multi target/os/arch

[MrCroxx]

What's changed and what's your intention?

Please explain IN DETAIL what the changes are in this PR and why they are needed. :D

As title. O_DIRECT value differs on different platforms.

// linux amd64
pub const O_DIRECT: ::c_int = 0x4000;
// linux aarch64
pub const O_DIRECT: ::c_int = 0x10000;

Checklist

• I have written the necessary rustdoc comments
• I have added the necessary unit tests and integration tests
• I have passed make all (or make fast instead if the old tests are not modified) in my local environment.

Related issues or PRs (optional)

#555

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.33%. Comparing base (3215bb1) to head (7f93a71).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #554      +/-   ##
==========================================
+ Coverage   86.32%   86.33%   +0.01%     
==========================================
  Files          58       58              
  Lines        7554     7554              
==========================================
+ Hits         6521     6522       +1     
+ Misses       1033     1032       -1     

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