Remove empty lines

Author: BertramScharpf

src/std_misc/fs.md

@@ -103,7 +103,6 @@ fn main() {
         println!("! {:?}", why.kind());
     });
 }
-
 ```
 
 Here's the expected successful output:

src/std_misc/path.md

@@ -45,7 +45,6 @@ fn main() {
         Some(s) => println!("new path is {}", s),
     }
 }
-
 ```
 
 Be sure to check at other `Path` methods (`posix::Path` or `windows::Path`) and

src/std_misc/threads/testcase_mapreduce.md

@@ -115,8 +115,6 @@ fn main() {
 
     println!("Final sum result: {}", final_result);
 }
-
-
 ```
 
 ### Assignments