go text remove extra space of script output

go-text-remove-extra-line.go

package main
import(
  "os/exec"
  "os"
  "fmt"
)

func main() {
  devices := getDevices()
  fmt.Println(devices)
  fmt.Println(len(devices))
}
func getDevices() []string {   
     ret, err := exec.Command("/sbin/smartctl", "--scan").Output()
     if err != nil {
         log.Println("Execute /sbin/smartctl --scan error: %v", err)
         os.Exit(-1)
     }   
     
     linest := strings.Split(string(ret), "\n")
     lines := linest[:len(linest)-1] // remove last extra line with output of bash command
     var devList = []string{}
     for _, line := range lines {
         device := strings.Fields(line)[0]
         devList = append(devList, device)
     }   
     
     return devList
 }

/*
remove extra line
[/dev/sda]
1

not remove extra line
[/dev/sda ]
2
*/