fix: Syntax error to fit formatting

exercises/024_errors4.zig

@@ -59,7 +59,7 @@ fn fixTooSmall(n: u32) MyNumberError!u32 {
     // If we get a TooSmall error, we should return 10.
     // If we get any other error, we should return that error.
     // Otherwise, we return the u32 number.
-    return detectProblems(n) ???
+    return detectProblems(n) ???;
 }
 
 fn detectProblems(n: u32) MyNumberError!u32 {