Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c
index 453a6a1..2b4d501 100644
--- a/fs/jffs2/background.c
+++ b/fs/jffs2/background.c
@@ -125,7 +125,7 @@
 			if (try_to_freeze())
 				goto again;
 
-			signr = kernel_dequeue_signal(NULL);
+			signr = kernel_dequeue_signal();
 
 			switch(signr) {
 			case SIGSTOP: