documentation: Clean up references to 'Gerrit2'

Now that the 2.x code base is over a year old, and has been in
production for almost a full year, its time to stop calling this
'Gerrit2' and start referring to it by the complete project name,
Gerrit Code Review.

Change-Id: Ifb37dd63b94ed7e1b938511aa0fc2a6ad3c981d6
Signed-off-by: Shawn O. Pearce <sop@google.com>
diff --git a/Documentation/user-signedoffby.txt b/Documentation/user-signedoffby.txt
index 4190c35..d07516a 100644
--- a/Documentation/user-signedoffby.txt
+++ b/Documentation/user-signedoffby.txt
@@ -1,5 +1,5 @@
-Gerrit2 - Signed-off-by Lines
-=============================
+Gerrit Code Review - Signed-off-by Lines
+=========================================
 
 [NOTE]
 This document was literally taken from link:http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/SubmittingPatches;hb=4e8a2372f9255a1464ef488ed925455f53fbdaa1[linux-2.6 Documentation/SubmittingPatches]