Fix format_in_format_args warnings

Signed-off-by: Joseph Livesey <joseph.livesey@btp.works>

Author: suchapalaver

perf/intkey_workload/src/main.rs

@@ -366,7 +366,7 @@ struct IntKeyCliError {
 
 impl fmt::Display for IntKeyCliError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", format!("IntKeyCliError {}", self.msg))
+        write!(f, "{}", format_args!("IntKeyCliError {}", self.msg))
     }
 }