vc-utils: don't export unused function

Many of these functions are just used on one place throughout the rest
of the code base. If we create hypervisor package, newtork package, etc, we may want to
parse this out.

Fixes: #3049

Signed-off-by: Eric Ernst <eric_ernst@apple.com>

src/runtime/virtcontainers/utils/utils.go

@@ -71,8 +71,8 @@ func GenerateRandomBytes(n int) ([]byte, error) {
 	return b, nil
 }
 
-// ReverseString reverses whole string
-func ReverseString(s string) string {
+// reverseString reverses whole string
+func reverseString(s string) string {
 	r := []rune(s)
 
 	length := len(r)
@@ -160,7 +160,7 @@ func GetVirtDriveName(index int) (string, error) {
 		return "", fmt.Errorf("Index not supported")
 	}
 
-	diskName := prefix + ReverseString(string(diskLetters[:i]))
+	diskName := prefix + reverseString(string(diskLetters[:i]))
 	return diskName, nil
 }
 

src/runtime/virtcontainers/utils/utils_test.go

@@ -97,7 +97,7 @@ func TestGenerateRandomBytes(t *testing.T) {
 func TestRevereString(t *testing.T) {
 	assert := assert.New(t)
 	str := "Teststr"
-	reversed := ReverseString(str)
+	reversed := reverseString(str)
 	assert.Equal(reversed, "rtstseT")
 }