docs: filesystems: fix renamed references

Some filesystem references got broken by a previous patch
series I submitted. Address those.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Acked-by: David Sterba <[email protected]> # fs/affs/Kconfig
Link: https://lore.kernel.org/r/57318c53008dbda7f6f4a5a9e5787f4d37e8565a.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <[email protected]>
diff --git a/fs/ecryptfs/Kconfig b/fs/ecryptfs/Kconfig
index 522c35d..1bdeaa6d 100644
--- a/fs/ecryptfs/Kconfig
+++ b/fs/ecryptfs/Kconfig
@@ -7,7 +7,7 @@
 	select CRYPTO_MD5
 	help
 	  Encrypted filesystem that operates on the VFS layer.  See
-	  <file:Documentation/filesystems/ecryptfs.txt> to learn more about
+	  <file:Documentation/filesystems/ecryptfs.rst> to learn more about
 	  eCryptfs.  Userspace components are required and can be
 	  obtained from <http://ecryptfs.sf.net>.