Meta+Kernel: Make clang-format-10 clean

Author: https://github.com/BenWiederhake
Commit: 64cc3f51d0
Pull-request: https://github.com/SerenityOS/serenity/pull/3541
Reviewed-by: https://github.com/alimpfard
Reviewed-by: https://github.com/linusg

Kernel/Syscalls/thread.cpp

@@ -159,7 +159,7 @@ int Process::sys$join_thread(pid_t tid, Userspace<void**> exit_value)
     thread = nullptr;
 
     if (exit_value && !copy_to_user(exit_value, &joinee_exit_value))
-       return -EFAULT;
+        return -EFAULT;
     return 0;
 }