fix piouff shit

src/robot.rs

@@ -88,10 +88,7 @@ pub fn is_instructions(v: &Vec<char>) -> bool {
 
 /// Check if a robot is piouff.
 pub fn is_piouff(r: &Robot) -> bool {
-    if r.i.len() == 0 {
-        return true;
-    }
-    false
+    r.i.len() == 0
 }
 
 /// Print robots id, position and instructions.