Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S
index b0b80c0..b11bba5 100644
--- a/arch/arm/xen/hypercall.S
+++ b/arch/arm/xen/hypercall.S
@@ -113,8 +113,7 @@
 
 	/*
 	 * Disable userspace access from kernel. This is fine to do it
-	 * unconditionally as no set_fs(KERNEL_DS)/set_fs(get_ds()) is
-	 * called before.
+	 * unconditionally as no set_fs(KERNEL_DS) is called before.
 	 */
 	uaccess_disable r4