tools: ynl: add script dir to sys.path

Python options like PYTHONSAFEPATH or -P [1] do not add script
directory to PYTHONPATH. ynl depends on this path to build and run.

[1] This option is default for Fedora rpmbuild since introduction of
https://fedoraproject.org/wiki/Changes/PythonSafePath

Signed-off-by: Jan Stancek <[e-mail]>
Acked-by: Jakub Kicinski <[e-mail]>
Reviewed-by: Donald Hunter <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/net/ynl/cli.py

···
 
 import argparse
 import json
+import pathlib
 import pprint
+import sys
 import time
 import signal
 
+sys.path.append(pathlib.Path(__file__).resolve().parent.as_posix())
 from lib import YnlFamily, Netlink, NlError
 
 

tools/net/ynl/ethtool.py

···
 
 import argparse
 import json
+import pathlib
 import pprint
 import sys
 import re
 import os
 
+sys.path.append(pathlib.Path(__file__).resolve().parent.as_posix())
 from lib import YnlFamily
 
 def args_to_req(ynl, op_name, args, req):

tools/net/ynl/ynl-gen-c.py

···
 import argparse
 import collections
 import filecmp
+import pathlib
 import os
 import re
 import shutil
+import sys
 import tempfile
 import yaml
 
+sys.path.append(pathlib.Path(__file__).resolve().parent.as_posix())
 from lib import SpecFamily, SpecAttrSet, SpecAttr, SpecOperation, SpecEnumSet, SpecEnumEntry