Fix go vet issues

Test: go vet ./...
Change-Id: Ifb936ccc5e2b5a2c3fcbbbcb54f680e2973ea1b3

android/config_test.go

@@ -50,7 +50,7 @@ func validateConfigAnnotations(configurable jsonConfigurable) (err error) {
 }
 
 type configType struct {
-	populateMe *bool `json:"omitempty"`
+	PopulateMe *bool `json:"omitempty"`
 }
 
 func (c *configType) SetDefaultConfig() {
@@ -60,7 +60,7 @@ func (c *configType) SetDefaultConfig() {
 func TestValidateConfigAnnotations(t *testing.T) {
 	config := configType{}
 	err := validateConfigAnnotations(&config)
-	expectedError := `Field configType.populateMe has tag json:"omitempty" which specifies to change its json field name to "omitempty".
+	expectedError := `Field configType.PopulateMe has tag json:"omitempty" which specifies to change its json field name to "omitempty".
 Did you mean to use an annotation of ",omitempty"?
 (Alternatively, to change the json name of the field, rename the field in source instead.)`
 	if err.Error() != expectedError {

android/makevars.go

@@ -153,7 +153,7 @@ func (s *makeVarsSingleton) GenerateBuildActions(ctx SingletonContext) {
 func (s *makeVarsSingleton) writeVars(vars []makeVarsVariable) []byte {
 	buf := &bytes.Buffer{}
 
-	fmt.Fprintln(buf, `# Autogenerated file
+	fmt.Fprint(buf, `# Autogenerated file
 
 # Compares SOONG_$(1) against $(1), and warns if they are not equal.
 #
@@ -201,7 +201,7 @@ my_check_failed := false
 		fmt.Fprintf(buf, "$(eval $(call soong-compare-var,%s,%s,my_check_failed := true))\n\n", v.name, sort)
 	}
 
-	fmt.Fprintln(buf, `
+	fmt.Fprint(buf, `
 ifneq ($(my_check_failed),false)
   $(error Soong variable check failed)
 endif

android/namespace.go

@@ -94,10 +94,8 @@ type NameResolver struct {
 }
 
 func NewNameResolver(namespaceExportFilter func(*Namespace) bool) *NameResolver {
-	namespacesByDir := sync.Map{}
-
 	r := &NameResolver{
-		namespacesByDir:       namespacesByDir,
+		namespacesByDir:       sync.Map{},
 		namespaceExportFilter: namespaceExportFilter,
 	}
 	r.rootNamespace = r.newNamespace(".")