Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/sparc/oprofile/init.c b/arch/sparc/oprofile/init.c
index f9024bc..43730c9 100644
--- a/arch/sparc/oprofile/init.c
+++ b/arch/sparc/oprofile/init.c
@@ -53,7 +53,7 @@
 {
 	nmi_adjust_hz(1);
 	unregister_die_notifier(&profile_timer_exceptions_nb);
-	synchronize_sched();  /* Allow already-started NMIs to complete. */
+	synchronize_rcu();  /* Allow already-started NMIs to complete. */
 }
 
 static int op_nmi_timer_init(struct oprofile_operations *ops)