crypto/x509: map/slice literals janitoring

Simplify slice/map literal expression.
Caught with gofmt -d -s, fixed with gofmt -w -s

Change-Id: I4472c6003cf66e65f6e69050872ff95c96f01253
Reviewed-on: https://go-review.googlesource.com/13836Reviewed-by: Andrew Gerrand <adg@golang.org>

src/crypto/x509/x509_test.go

@@ -504,9 +504,9 @@ func TestUnknownCriticalExtension(t *testing.T) {
 
 	oids := []asn1.ObjectIdentifier{
 		// This OID is in the PKIX arc, but unknown.
-		asn1.ObjectIdentifier{2, 5, 29, 999999},
+		{2, 5, 29, 999999},
 		// This is a nonsense, unassigned OID.
-		asn1.ObjectIdentifier{1, 2, 3, 4},
+		{1, 2, 3, 4},
 	}
 
 	for _, oid := range oids {