Update notes for submitted changes

* Use constant for ".lock"
* Simplify locking of FileRepository's index snapshot

1c/b8c5d7fe2d88c127bafcff3800b91e5ab5eda4

@@ -0,0 +1,8 @@
+Verified+1: CI Bot
+Code-Review+1: Thomas Wolf <thomas.wolf@paranor.ch>
+Code-Review+2: Jonathan Nieder <jrn@google.com>
+Submitted-by: Jonathan Nieder <jrn@google.com>
+Submitted-at: Fri, 08 Jun 2018 16:38:45 -0400
+Reviewed-on: https://git.eclipse.org/r/124235
+Project: jgit/jgit
+Branch: refs/heads/stable-5.0

5f/27032fb85694a093f827581216d4ffb99db68b

@@ -0,0 +1,7 @@
+Verified+1: CI Bot
+Code-Review+2: Jonathan Nieder <jrn@google.com>
+Submitted-by: Jonathan Nieder <jrn@google.com>
+Submitted-at: Fri, 08 Jun 2018 16:38:45 -0400
+Reviewed-on: https://git.eclipse.org/r/124271
+Project: jgit/jgit
+Branch: refs/heads/stable-5.0