修改字符串错误方法名

eBook/06.4.md

@@ -15,13 +15,13 @@ func main() {
 }
 
 func function1() {
-	fmt.Printf("In Function1 at the top\n")
+	fmt.Printf("In function1 at the top\n")
 	defer function2()
-	fmt.Printf("In Function1 at the bottom!\n")
+	fmt.Printf("In function1 at the bottom!\n")
 }
 
 func function2() {
-	fmt.Printf("Function2: Deferred until the end of the calling function!")
+	fmt.Printf("function2: Deferred until the end of the calling function!")
 }
 ```