examples: fix warnings when doing ./v -W -progress -check-syntax build-examples

examples/hanoi.v

@@ -4,21 +4,21 @@ const (
 )
 
 fn main() {
-	hanoi(num, 'A','B','C')
+	hanoi(num, 'A', 'B', 'C')
 }
 
-fn move(n int, a, b string) int {
+fn move(n int, a string, b string) int {
 	println('Disc $n from $a to $b\...')
 	return 0
 }
 
-fn hanoi(n int, a, b, c string) int {
+fn hanoi(n int, a string, b string, c string) int {
 	if n == 1 {
-		move(1,a,c)
+		move(1, a, c)
 	} else {
-		hanoi(n-1, a, c, b)
-		move(n,a,c)
-		hanoi(n-1, b, a, c)
+		hanoi(n - 1, a, c, b)
+		move(n, a, c)
+		hanoi(n - 1, b, a, c)
 	}
 	return 0
 }