Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/filesystems/nfs/nfsroot.txt b/Documentation/filesystems/nfs/nfsroot.txt
index d296312..ae43324 100644
--- a/Documentation/filesystems/nfs/nfsroot.txt
+++ b/Documentation/filesystems/nfs/nfsroot.txt
@@ -239,7 +239,7 @@
   A description of the process of mounting the root file system can be
   found in:
 
-    Documentation/early-userspace/README
+    Documentation/driver-api/early-userspace/early_userspace_support.rst