Remove platform-specific hint

Co-authored-by: Viktor Dukhovni <viktor1ghub@dukhovni.org>

Author: 2 people

System/Posix/IO.hsc

@@ -89,8 +89,6 @@ openFd = openFdAt Nothing
 -- navigating changing directory trees, or to retain access to a portion of the
 -- directory tree that would otherwise become inaccessible after dropping
 -- privileges.
---
--- It is currently not possible to obtain a file-descriptor to a symbolic link, they will always be dereferenced. See note in 'OpenFileFlags'.
 openFdAt :: Maybe Fd -- ^ Optional directory file descriptor
          -> FilePath -- ^ Pathname to open
          -> OpenMode -- ^ Read-only, read-write or write-only