enclave_build: fix clippy failure

Add missing truncate behavior to the open options.

Signed-off-by: Erdem Meydanli <[email protected]>

enclave_build/src/main.rs

@@ -144,6 +144,7 @@ fn main() {
         .read(true)
         .write(true)
         .create(true)
+        .truncate(true)
         .open(output)
         .expect("Failed to create output file");