drivers/syslog: remove implement of syslog_putc()

[anchao]

Summary

drivers/syslog: remove implement of syslog_putc()

syslog_putc() have a lot of duplicate logic with syslog_write().
remove syslog_putc() and reuse syslog_write() to simplify syslog printing.

Signed-off-by: chao an [email protected]

Impact

N/A

Testing

ci-check

[nuttxpr]

[Experimental Bot, please feedback here]

No, this PR does not fully meet the NuttX requirements. While it provides a summary and testing information, it lacks crucial details.

Here's what's missing:

• Summary: While it states what is being changed, it doesn't fully explain why. What are the benefits of removing syslog_putc() besides "simplifying"? Does it improve performance, reduce code size, or fix a bug? This is the most important part of the summary and needs to be strengthened. It also needs links to related issues if applicable.
• Impact: Simply stating "N/A" is insufficient. Each impact item needs to be explicitly addressed with either "NO" or "YES (with explanation)". Even if there's no impact, stating "NO" for each item demonstrates that the impact has been considered. For example, are you sure there's no impact on compatibility? Could code relying on syslog_putc() break?
• Testing: "ci-check" is not sufficient. While CI is important, the requirements specifically request testing logs before and after the change. These logs should demonstrate that the change works as intended and doesn't introduce regressions. What specific tests were run? Provide concrete examples, even if simple. Also, specify the build host and target details as requested.

Therefore, while the PR provides a starting point, it needs more information before it can be considered complete according to the provided guidelines.

[yamt]

why?

[anchao]

showprocess() is only called during the startup phase, up_putc is more suitable

[yamt]

what's the point of this ifdef block then?