src.ctf.fs: make log macros of data-stream-file.c more generic

src.ctf.fs: make log macros of data-stream-file.c more generic

The logging macros in data-stream-file.c currently assume that all the
contexts where a logging statement is used will have a self component at
ds_file->self_comp and a logging level at ds_file->log_level.  In a
future patch, I'd like to use a logging statement where there is no
reason to pass a ds_file variable.

Make the macros more generic by having them refer to just self_comp and
logging_level.

Change-Id: I0057dd27310e6ca6bf18441e214eb2fe8a25b19e
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/2326
Tested-by: jenkins <jenkins@lttng.org>