ubifs: free the encrypted symlink target

ubifs: free the encrypted symlink target

commit 6b46d444146eb8d0b99562795cea8086639d7282 upstream.

ubifs_symlink() forgot to free the kmalloc()'ed buffer holding the
encrypted symlink target, creating a memory leak.  Fix it.

(UBIFS could actually encrypt directly into ui->data, removing the
temporary buffer, but that is left for the patch that switches to use
the symlink helper functions.)

Fixes: ca7f85be8d6c ("ubifs: Add support for encrypted symlinks")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>