update _stringify_path doc

Author: CRiddler

nibabel/filename_parser.py

@@ -25,13 +25,14 @@ def _stringify_path(filepath_or_buffer):
 
     Returns
     -------
-    str_filepath_or_buffer : maybe a string version of the object
+    str_filepath_or_buffer : str
+    
     Notes
     -----
     Objects supporting the fspath protocol (python 3.6+) are coerced
     according to its __fspath__ method.
-    For backwards compatibility with older pythons, pathlib.Path and
-    py.path objects are specially coerced.
+    For backwards compatibility with older pythons, pathlib.Path objects 
+    are specially coerced.
     Any other object is passed through unchanged, which includes bytes,
     strings, buffers, or anything else that's not even path-like.