[submodule_update] Minor cleanups

Delete unused variables, make sure to add a newline at the end of printf
calls.

Change-Id: I197f7b9f35949613bfa9addae31498cf2c7b381d
Reviewed-on: https://fuchsia-review.googlesource.com/c/infra/infra/+/980373
Reviewed-by: Ina Huh <ihuh@google.com>
Fuchsia-Auto-Submit: Oliver Newman <olivernewman@google.com>
Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>
diff --git a/cmd/submodule_update/base.go b/cmd/submodule_update/base.go
index 604f7bf..62fedd8 100644
--- a/cmd/submodule_update/base.go
+++ b/cmd/submodule_update/base.go
@@ -9,13 +9,11 @@
 )
 
 type baseCmd struct {
-	resultPath string
 	jsonInput  string
 	jsonOutput string
 }
 
 func (b *baseCmd) SetFlags(f *flag.FlagSet) {
-	f.StringVar(&b.resultPath, "result_path", "", "path to where json result file should be written")
 	f.StringVar(&b.jsonInput, "json-input", "", "Path to JSON inputs.")
 	f.StringVar(&b.jsonOutput, "json-output", "", "Path to output results.")
 }
diff --git a/cmd/submodule_update/integration_update.go b/cmd/submodule_update/integration_update.go
index 819530c..dabf680 100644
--- a/cmd/submodule_update/integration_update.go
+++ b/cmd/submodule_update/integration_update.go
@@ -111,11 +111,11 @@
 
 func (p *integrationUpdateCmd) Execute(_ context.Context, _ *flag.FlagSet, _ ...any) subcommands.ExitStatus {
 	if err := p.Validate(); err != nil {
-		fmt.Printf("error: %v", err)
+		fmt.Printf("error: %s\n", err)
 		return subcommands.ExitFailure
 	}
 	if err := p.ParseJSON(); err != nil {
-		fmt.Printf("error: %v", err)
+		fmt.Printf("error: %s\n", err)
 		return subcommands.ExitFailure
 	}
 	fmt.Printf("Updating superproject %s to integration.git revision %s on branch %s\n", p.updateConfig.SuperprojectRoot, p.updateConfig.CurrentRevision, p.updateConfig.Branch)
diff --git a/cmd/submodule_update/main.go b/cmd/submodule_update/main.go
index c3f0ba3..707da9b 100644
--- a/cmd/submodule_update/main.go
+++ b/cmd/submodule_update/main.go
@@ -14,11 +14,6 @@
 	"github.com/google/subcommands"
 )
 
-var (
-	superprojectRoot *string
-	resultPath       *string
-)
-
 func main() {
 	if err := flag.Set("alsologtostderr", "true"); err != nil {
 		log.Fatal(err)
diff --git a/cmd/submodule_update/submodule_update.go b/cmd/submodule_update/submodule_update.go
index ea8d5c2..8395917 100644
--- a/cmd/submodule_update/submodule_update.go
+++ b/cmd/submodule_update/submodule_update.go
@@ -46,7 +46,7 @@
 
 func (p *submoduleUpdateCmd) Execute(_ context.Context, _ *flag.FlagSet, _ ...any) subcommands.ExitStatus {
 	if err := p.Validate(); err != nil {
-		fmt.Printf("error: %v", err)
+		fmt.Printf("error: %s\n", err)
 		return subcommands.ExitFailure
 	}
 	fmt.Printf("%s %s to revision %s\n", p.operation, p.submodulePath, p.revision)