Fix: 06 - Conditionals

Simplified max_of_three.

modules/02_control_flow/src/conditionals.cpp

@@ -13,11 +13,10 @@ auto classify_score(const int score) -> Grade {
 auto max_of_three(const int a, const int b, const int c) -> int {
     if (a >= b) {
         if (a >= c) return a;
-        if (c > a) return c;
+        return c;
     }
     if (b >= c) return b;
-    if (c > b) return c;
-    return -1;
+    return c;
 }
 
 auto sign_of(const int value) -> int {