Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index d5f9a2d..0117489 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -1,7 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
  * Copyright (C) 2001 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
  */
 
 #include <linux/console.h>
@@ -96,7 +96,6 @@
 	}
 	if (!list_empty(&mc_requests))
 		schedule_work(&mconsole_work);
-	reactivate_fd(fd, MCONSOLE_IRQ);
 	return IRQ_HANDLED;
 }
 
@@ -240,7 +239,6 @@
 		(*req->cmd->handler)(req);
 	}
 	os_set_fd_block(req->originating_fd, 0);
-	reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
 	mconsole_reply(req, "", 0, 0);
 }