Add helper method to exit with error code

cmd/lume/main.go

@@ -1,16 +1,11 @@
 package main
 
 import (
-	"fmt"
 	"os"
 
 	lumecmd "git.kill0.net/chill9/lume/cmd"
 )
 
 func main() {
-	exitCode, err := lumecmd.Main(os.Args)
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "%s\n", err)
-	}
-	os.Exit(exitCode)
+	lumecmd.ExitWithCode(lumecmd.Main(os.Args))
 }

cmd/util.go

@@ -2,6 +2,7 @@ package lumecmd
 
 import (
 	"fmt"
+	"os"
 	"sort"
 	"strconv"
 	"strings"
@@ -151,3 +152,10 @@ func sortResults(res []lifx.Result) {
 		return res[i].Label < res[j].Label
 	})
 }
+
+func ExitWithCode(code int, err error) {
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%s\n", err)
+	}
+	os.Exit(code)
+}