BUG/MINOR: log: Add OOM checks for calloc() and malloc() in logformat parser and...

BUG/MINOR: log: Add OOM checks for calloc() and malloc() in logformat parser and dup_logger()

This patch adds missing out-of-memory (OOM) checks after calls
to `calloc()` and `malloc()` in the logformat parser and the
`dup_logger()` function. If memory allocation fails, an error
is reported or NULL is returned, preventing undefined behavior
in low-memory conditions.

Co-authored-by: Christian Norbert Menges <christian.norbert.menges@sap.com>