Fix file rotation failure in offline storage

[quzn]

Description

Fixes a bug where the dlt-daemon fails to rotate log files in offline storage mode due to fd unavailable.

Issue Manifestation

• During initial storage, when no log files exist in the designated directory, rotation occurs correctly as configured in dlt_logstorage.conf
• Upon device reboot, when historical log files are present in the storage directory, there exists a probability of rotation failure, resulting in indefinite growth of a single file. The failure probability exhibits an inverse correlation with the FileSize parameter configured in the filter.

Trigger Conditions

• When writing the first log message after device reboot, if the combined size of the most recent historical log file and the current message exceeds the configured file size threshold

Example scenario:

• Config->FileSize: 1000
• LatestFileSize: 900
• LogMessage: 110

Root Cause

The file handle acquisition function fails to execute, leaving the file handle with its default invalid value.

[minminlittleshrimp]

need utest

[quzn]

OK, will add utest later. Thanks!