-init-pred yields illegal SMT2 code

[mattulbrich]

If -init-pred is used as command-line parameter, the program produces illegal SMT2 code which has nested assert commands.

(assert
   (assert
      (forall
         ((n$1_0 Int)
          (n$2_0 Int))
         (=>
            (IN_INV n$1_0 n$2_0)
            (INIT n$1_0 n$2_0)))))