Review: simpler implementation and test

Because **all** the path are bytestrings

beets/util/__init__.py

@@ -227,8 +227,6 @@ def path_as_posix(path):
     """Return the string representation of the path with forward (/)
     slashes.
     """
-    if isinstance(path, str):
-        return path.replace('\\', '/')
     return path.replace(b'\\', b'/')
 
 

test/test_files.py

@@ -196,8 +196,8 @@ class HelperTest(_common.TestCase):
         self.assertEqual(util.components(p), a)
 
     def test_forward_slash(self):
-        p = r'C:\a\b\c'
-        a = r'C:/a/b/c'
+        p = br'C:\a\b\c'
+        a = br'C:/a/b/c'
         self.assertEqual(util.path_as_posix(p), a)