Merge pull request #1569 from crjg-k/patch-1

Update drop.md

src/advance/smart-pointer/drop.md

@@ -43,7 +43,7 @@ struct Foo;
 
 impl Drop for Foo {
     fn drop(&mut self) {
-        println!("Dropping Foo!")
+        println!("Dropping Foo!");
     }
 }