Traffic is impacted due to PFE crash from ukern file logging

While maintaining PFE's ukern files, the SYSLOG handler sends a signal to the PFE when the file is being archived, and repeated memory allocation is done to process this signal for file-logging, which causes memory leak and corruption. There might be a PFE crash as a result.

On Junos EX platforms, the PFE's (Packet Forwarding Engine) handling of NEWSYSLOGD signals during UKERN file archiving is inefficient, leading to repeated memory allocations and subsequent memory leaks.

This issue might be seen if the following conditions are met:
* On Junos EX platforms (EX4100, EX2300, EX3400, EX4400)
* UKERN_GBL file-logging enabled in the PFE (it's enabled by default)

Resolved through https://prsearch.juniper.net/problemreport/PR1831813