src.ctf.fs: remove ctf_fs_file_create

src.ctf.fs: remove ctf_fs_file_create

Remove this function, it's now just a wrapper around constructing a
ctf_fs_file.

Change-Id: I95e4d6eb26b0d359e0f480cac51af11f3a1db539
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/8297
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/12333
Tested-by: jenkins <jenkins@lttng.org>