MailboxDriver: clippy findings

Change-Id: I116cce53a531915916d0a3509f3324e9694b1293
GitOrigin-RevId: a816c6ea0d3ca42cfc75d5b88cf7795fb99b63f6

apps/system/components/MailboxDriver/mailbox-driver/src/lib.rs

@@ -2,6 +2,7 @@
 // We want to keep all mailbox constants here even if they're currently unused.
 #![allow(dead_code)]
 #![allow(non_snake_case)]
+#![allow(clippy::missing_safety_doc)]
 
 use kata_os_common::logger::KataLogger;
 use log::{error, trace};
@@ -158,7 +159,7 @@ fn enqueue_u32(x: u32) {
 fn dequeue_u32() -> u32 {
     unsafe {
         while (get_STATUS() & STATUS_BIT_EMPTY) == STATUS_BIT_EMPTY {}
-        return get_MBOXR();
+        get_MBOXR()
     }
 }