Fix incorrect timestamp assignment when writing inode

[EricKim27]

fix simplefs_write_inode to write the access time into disk_inode->i_atime and the modification time into disk_inode->i_mtime correctly.

After an inode has been modified or created, simplefs_write_inode(assigned to write_inode in simplefs_super_ops) is called to write the contents in the vfs inode to the relevant raw inode on disk. Because of a typo in simplefs_write_inode, i_atime gets assigned twice; once for writing access time, and again for writing modification time to it.

As a result, the raw inode metadata contains modification time on its access time field, and the modification time is never updated. Upon calling system calls like stat(), it returns modification time as access time, and an incorrect modification time(since it is never updated, and all bytes are zeroed out at mkfs, it defaults to 0, January 1st, 1970 in unix time).

Fix the assignments so access time is written to i_atime field and modification time is written to i_mtime field on on-disk inode structure.

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Summary by cubic

Fixes mtime not updating by correcting a typo in super.c: write to i_mtime instead of i_atime in simplefs_write_inode for kernel >= 6.7. Files now record and show the correct modification time instead of 1970-01-01.

^{Written for commit 94e6f18. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 1 file

_{Re-trigger cubic}

[jserv]

Improve git commit messages per https://cbea.ms/git-commit/

[EricKim27]

@jserv Modified the commit message as requested. Thanks for your feedback.

[jserv]

Modified the commit message as requested.

Check https://cbea.ms/git-commit/ carefully and improve git commit messages to address motivations and considerations.

[EricKim27]

Modified the commit message as requested.

Check https://cbea.ms/git-commit/ carefully and improve git commit messages to address motivations and considerations.

I read the article you provided to me and improved the messages that would address my motivations and considerations. Thanks for the feedback.