Tools: use path relative to current directory to load parameters

Tools/autotest/pysim/util.py

@@ -57,6 +57,9 @@ def topdir():
     d = os.path.dirname(d)
     return d
 
+def relcurdir(path):
+    """Return a path relative to current dir"""
+    return os.path.relpath(path, os.getcwd())
 
 def reltopdir(path):
     """Return a path relative to topdir()."""

Tools/autotest/sim_vehicle.py

@@ -684,7 +684,7 @@ def start_vehicle(binary, opts, stuff, spawns=None):
         paths = stuff["default_params_filename"]
         if not isinstance(paths, list):
             paths = [paths]
-        paths = [util.reltopdir(os.path.join(autotest_dir, x)) for x in paths]
+        paths = [util.relcurdir(os.path.join(autotest_dir, x)) for x in paths]
         for x in paths:
             if not os.path.isfile(x):
                 print("The parameter file (%s) does not exist" % (x,))