When the file is in the current path, an error will be reported. (#113)

Co-authored-by: Tim 'mithro' Ansell <me@mith.ro>

v2x/vlog_to_pbtype.py

diff --git a/v2x/vlog_to_pbtype.py b/v2x/vlog_to_pbtype.py
index de5db80..b2f6bcd 100755
--- a/v2x/vlog_to_pbtype.py
+++ b/v2x/vlog_to_pbtype.py
@@ -580,7 +580,9 @@
         module_prefix = re.match(r"([A-Za-z0-9_]+)\.sim\.v",
                                  module_basename).groups()[0]
 
-        pb_type_path = "{}/{}.pb_type.xml".format(module_path, module_prefix)
+        pb_type_path = "{}.pb_type.xml".format(module_prefix)
+        if module_path:
+            pb_type_path = os.path.join(module_path, pb_type_path)
 
         include_as_is = True
         comment_str = ""