Fix some ssreflect tactic printing code
Fix some ssreflect tactic printing code

Testcases:

```
Require Import ssreflect.

Ltac t a b c := set a : b := c.
Print t.
(* set  a  :  := c -> set  a  : b := c *)

Ltac u a b := set a := b.
Print u.
(* set  a  :  := b -> set  a  := b *)

Ltac v a b c d := set a : b := {1}d.
Print v.
(* set  a  :  := d -> set  a  : b := {+1}d *)

Ltac w a b := have: a by b.
Print w.
(* have : aby b -> have : a by b *)
```

SkySkimmer/coq,coq/coq,ejgallego/coq,coq/coq,coq/coq,SkySkimmer/coq,ejgallego/coq,Zimmi48/coq,SkySkimmer/coq,coq/coq,ejgallego/coq,Zimmi48/coq,Zimmi48/coq,SkySkimmer/coq,Zimmi48/coq,ejgallego/coq