LibCore+flock: Make Core::System::waitpid more ergonomic

Author: https://github.com/juniorrantila
Commit: 0d328f3c86
Pull-request: https://github.com/SerenityOS/serenity/pull/11790
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/kleinesfilmroellchen ✅

Userland/Libraries/LibCore/System.cpp

@@ -517,12 +517,13 @@ ErrorOr<pid_t> posix_spawnp(StringView const path, posix_spawn_file_actions_t* c
     return child_pid;
 }
 
-ErrorOr<pid_t> waitpid(pid_t waitee, int* wstatus, int options)
+ErrorOr<WaitPidResult> waitpid(pid_t waitee, int options)
 {
-    pid_t pid = ::waitpid(waitee, wstatus, options);
+    int wstatus;
+    pid_t pid = ::waitpid(waitee, &wstatus, options);
     if (pid < 0)
         return Error::from_syscall("waitpid"sv, -errno);
-    return pid;
+    return WaitPidResult { pid, wstatus };
 }
 
 ErrorOr<void> setuid(uid_t uid)