fix: avoid SIGSEGV in read_proc_io during static initialization

[jesson1]

What problem does this PR solve?

Issue Number: resolve #3183

Problem Summary:
When /proc/self/io is inaccessible, read_proc_io calls PLOG during global static construction. If glog is not yet initialized, it triggers a SIGSEGV.

What is changed and the side effects?

Changed:
Replace PLOG_ONCE with a guarded fprintf(stderr, ...) to ensure safety during early startup. A static flag is used to maintain the "print once" behavior.

Side effects:

• Performance effects: none

• Breaking backward compatibility: none

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Check List:

• Please make sure your changes are compilable.
• When providing us with a new feature, it is best to add related tests.
• Please follow Contributor Covenant Code of Conduct.

[wwbmmm]

LGTM

[chenBright]

LGTM