cmd/link: accept Windows line-ending in TestTrampolineCgo

Apparently C printf emits "\r\n" on Windows. Accept that.

Change-Id: If87ba41435e3147d3892cfc3fe3a105b066ff0aa
Reviewed-on: https://go-review.googlesource.com/c/go/+/322973
Trust: Cherry Mui <[email protected]>
Run-TryBot: Cherry Mui <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Than McIntosh <[email protected]>

Author: cherrymui

src/cmd/link/link_test.go

@@ -698,7 +698,7 @@ func TestTrampolineCgo(t *testing.T) {
 	if err != nil {
 		t.Errorf("executable failed to run: %v\n%s", err, out)
 	}
-	if string(out) != "hello\n" {
+	if string(out) != "hello\n" && string(out) != "hello\r\n" {
 		t.Errorf("unexpected output:\n%s", out)
 	}
 
@@ -717,7 +717,7 @@ func TestTrampolineCgo(t *testing.T) {
 	if err != nil {
 		t.Errorf("executable failed to run: %v\n%s", err, out)
 	}
-	if string(out) != "hello\n" {
+	if string(out) != "hello\n" && string(out) != "hello\r\n" {
 		t.Errorf("unexpected output:\n%s", out)
 	}
 }