cifs: remove repeated state change in dfs tree connect

cifs_tree_connect checks and sets the tidStatus for the tcon.
cifs_tree_connect also calls a dfs specific tree connect
function, which also does similar checks. This should
not happen. Removing it with this change.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>