Fix 'dict' object has no attribute split

After updating to 2015.5.5 the state calls of win_path.exists suddenly were broken due to the change in the reg.py module.
This commit fixes the win_path.exists read_key implementation to fit the reg.read_value implementation that was discussed in https://github.com/saltstack/salt/issues/25618

salt/modules/win_path.py

@@ -74,7 +74,8 @@ def get_path():
     '''
     ret = __salt__['reg.read_key']('HKEY_LOCAL_MACHINE',
                                    'SYSTEM\\CurrentControlSet\\Control\\Session Manager\\Environment',
-                                   'PATH').split(';')
+                                   'PATH')
+    ret = ret['vdata'].split(';')
 
     # Trim ending backslash
     return list(map(_normalize_dir, ret))