Reapply "SYSLOG_DEFAULT: wrap up_putc/up_nputs calls with critical section" with a fix

[yamt]

Summary

Reapply "SYSLOG_DEFAULT: wrap up_putc/up_nputs calls with critical section" with a fix.

original change #14722
a revert #14751

Impact

Testing

• esp32-devkitc:wifi_smp (smp)
• esp32s3-devkit:smp (ostest, smp)
  (with semaphore: Fix a few regressions #14755 and a few other unrelated local patches)

[nuttxpr]

[Experimental Bot, please feedback here]

No. The PR is missing critical information required by the NuttX template.

• Summary: While it mentions the original PR and revert, it lacks a clear explanation of why the reapplication is necessary and how the fix addresses the issues that led to the revert. What exactly was the fix?
• Impact: The entire Impact section is missing. All fields should be addressed with either "NO" or a "YES" + explanation. This is crucial for reviewers to understand the potential consequences of the change.
• Testing: While targets are listed, the "Testing logs before change" and "Testing logs after change" sections are empty. This makes it impossible to verify the effectiveness of the fix. What were the symptoms of the bug before, and how do the logs demonstrate that the bug is now resolved? Furthermore, mentioning "a few other unrelated local patches" raises concerns; testing should ideally be done on a clean branch to isolate the effects of the PR.

Therefore, the PR in its current state does not meet the NuttX requirements. It needs substantial additions to be considered complete.

[pussuw]

LGTM. This also fixes recursive panic/assertion for me when trying to take the spinlock from assert!

[xiaoxiang781216]

@yamt please fix the following warning:

Error: syslog/syslog_channel.c:231:13: error: 'csection_available' defined but not used [-Werror=unused-function]
 static bool csection_available(void)
             ^