Don't use a type guard with a type which is not an interface.

R=r,gri
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=18781
CL=18785
diff --git a/test/ken/interbasic.go b/test/ken/interbasic.go
index e4b0b79..05eea39 100644
--- a/test/ken/interbasic.go
+++ b/test/ken/interbasic.go
@@ -86,7 +86,7 @@
 	u64 = 765432;	ia[12] = u64;
 
 	s = ia[0];	if s != "xxx" { panicln(0,s); }
-	i32 = ia[1].(int).(int32);
+	i32 = int32(ia[1].(int));
 			if i32 != 12345 { panicln(1,i32); }
 	b = ia[2];	if b != true { panicln(2,b); }