rust: remove redundant format in unreachable am: ff062d54f9 am: 7d8dde4b8f am: 2d4d0158ac am: 0a1a6fd4ae am: c4744ab7c4

Original change: https://android-review.googlesource.com/c/platform/external/minijail/+/2058807

Change-Id: I189c1f1a48ba08d9d17129215cfd59f398ec89f2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/rust/minijail/src/lib.rs b/rust/minijail/src/lib.rs
index cfba237..5028041 100644
--- a/rust/minijail/src/lib.rs
+++ b/rust/minijail/src/lib.rs
@@ -401,7 +401,7 @@
     if ret > 0 && ret <= 0xff {
         return Err(Error::ReturnCode(ret as u8));
     }
-    unreachable!(format!("Unexpected returned value from wait: {}", ret));
+    unreachable!("Unexpected returned value from wait: {}", ret);
 }
 
 impl Minijail {