Cleaned up else per golint

When an if ends in a return the else is not required. golint
detects these conditions and found these.

app.go

@@ -189,11 +189,10 @@ func (a *App) Run(arguments []string) (err error) {
 			err := a.OnUsageError(context, err, false)
 			HandleExitCoder(err)
 			return err
-		} else {
-			fmt.Fprintf(a.Writer, "%s\n\n", "Incorrect Usage.")
-			ShowAppHelp(context)
-			return err
 		}
+		fmt.Fprintf(a.Writer, "%s\n\n", "Incorrect Usage.")
+		ShowAppHelp(context)
+		return err
 	}
 
 	if !a.HideHelp && checkHelp(context) {
@@ -310,11 +309,10 @@ func (a *App) RunAsSubcommand(ctx *Context) (err error) {
 			err = a.OnUsageError(context, err, true)
 			HandleExitCoder(err)
 			return err
-		} else {
-			fmt.Fprintf(a.Writer, "%s\n\n", "Incorrect Usage.")
-			ShowSubcommandHelp(context)
-			return err
 		}
+		fmt.Fprintf(a.Writer, "%s\n\n", "Incorrect Usage.")
+		ShowSubcommandHelp(context)
+		return err
 	}
 
 	if len(a.Commands) > 0 {

command.go

@@ -132,12 +132,11 @@ func (c Command) Run(ctx *Context) (err error) {
 			err := c.OnUsageError(ctx, err, false)
 			HandleExitCoder(err)
 			return err
-		} else {
-			fmt.Fprintln(ctx.App.Writer, "Incorrect Usage.")
-			fmt.Fprintln(ctx.App.Writer)
-			ShowCommandHelp(ctx, c.Name)
-			return err
 		}
+		fmt.Fprintln(ctx.App.Writer, "Incorrect Usage.")
+		fmt.Fprintln(ctx.App.Writer)
+		ShowCommandHelp(ctx, c.Name)
+		return err
 	}
 
 	nerr := normalizeFlags(c.Flags, set)

flag.go

@@ -182,9 +182,8 @@ func (f *IntSlice) Set(value string) error {
 	tmp, err := strconv.Atoi(value)
 	if err != nil {
 		return err
-	} else {
-		*f = append(*f, tmp)
 	}
+	*f = append(*f, tmp)
 	return nil
 }