Update hpke_test.go.

Test needs to be updated to reflect
7fffa4636cf7647daf981914286d5d32f1beab6d.

Change-Id: I0eeb7c1058c57d36939865902ebfac2eaa2ca05d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/48305
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/ssl/test/runner/hpke/hpke_test.go b/ssl/test/runner/hpke/hpke_test.go
index e8c7544..a3aa4e7 100644
--- a/ssl/test/runner/hpke/hpke_test.go
+++ b/ssl/test/runner/hpke/hpke_test.go
@@ -38,7 +38,7 @@
 
 // Simple round-trip test for fixed inputs.
 func TestRoundTrip(t *testing.T) {
-	publicKeyR, secretKeyR, err := GenerateKeyPair()
+	publicKeyR, secretKeyR, err := GenerateKeyPairX25519()
 	if err != nil {
 		t.Errorf("failed to generate key pair: %s", err)
 		return