2017/state-of-go/stdlib/sort: fix build on 32-bit plaforms

Change-Id: I071e77d972c6fba474e00b2661cc9966bec56826
Reviewed-on: https://go-review.googlesource.com/37297
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
diff --git a/2017/state-of-go/stdlib/sort/sort_test.go b/2017/state-of-go/stdlib/sort/sort_test.go
index 0c50905..6e58d64 100644
--- a/2017/state-of-go/stdlib/sort/sort_test.go
+++ b/2017/state-of-go/stdlib/sort/sort_test.go
@@ -12,7 +12,7 @@
 type Person struct {
 	Name     string
 	AgeYears int
-	SSN      int
+	SSN      int64
 }
 
 type byName []Person
@@ -59,7 +59,7 @@
 	p := make([]Person, n)
 	for i := range p {
 		p[i].AgeYears = rand.Intn(100)
-		p[i].SSN = rand.Intn(10000000000)
+		p[i].SSN = rand.Int63n(1000000000)
 		p[i].Name = fmt.Sprintf("Mr or Ms %d", p[i].AgeYears)
 	}
 	return p