builder/digitalocean: fix incorrect printf verb types

Fixes the following vet reports:

builder/digitalocean/builder_test.go:267: arg b.config.SSHUsername for printf verb %d of wrong type: string
builder/digitalocean/builder_test.go:300: arg b.config.RawSSHTimeout for printf verb %d of wrong type: string
builder/digitalocean/builder_test.go:341: arg b.config.RawStateTimeout for printf verb %d of wrong type: string
builder/digitalocean/builder_test.go:382: arg b.config.PrivateNetworking for printf verb %s of wrong type: bool
builder/digitalocean/builder_test.go:397: arg b.config.PrivateNetworking for printf verb %s of wrong type: bool

builder/digitalocean/builder_test.go

@@ -264,7 +264,7 @@ func TestBuilderPrepare_SSHUsername(t *testing.T) {
 	}
 
 	if b.config.SSHUsername != "root" {
-		t.Errorf("invalid: %d", b.config.SSHUsername)
+		t.Errorf("invalid: %s", b.config.SSHUsername)
 	}
 
 	// Test set
@@ -297,7 +297,7 @@ func TestBuilderPrepare_SSHTimeout(t *testing.T) {
 	}
 
 	if b.config.RawSSHTimeout != "1m" {
-		t.Errorf("invalid: %d", b.config.RawSSHTimeout)
+		t.Errorf("invalid: %s", b.config.RawSSHTimeout)
 	}
 
 	// Test set
@@ -338,7 +338,7 @@ func TestBuilderPrepare_StateTimeout(t *testing.T) {
 	}
 
 	if b.config.RawStateTimeout != "6m" {
-		t.Errorf("invalid: %d", b.config.RawStateTimeout)
+		t.Errorf("invalid: %s", b.config.RawStateTimeout)
 	}
 
 	// Test set
@@ -379,7 +379,7 @@ func TestBuilderPrepare_PrivateNetworking(t *testing.T) {
 	}
 
 	if b.config.PrivateNetworking != false {
-		t.Errorf("invalid: %s", b.config.PrivateNetworking)
+		t.Errorf("invalid: %t", b.config.PrivateNetworking)
 	}
 
 	// Test set
@@ -394,7 +394,7 @@ func TestBuilderPrepare_PrivateNetworking(t *testing.T) {
 	}
 
 	if b.config.PrivateNetworking != true {
-		t.Errorf("invalid: %s", b.config.PrivateNetworking)
+		t.Errorf("invalid: %t", b.config.PrivateNetworking)
 	}
 }