pack-objects doesn't create random pack names

Documentation for pack-objects seems to be out of date in this regard.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-pack-objects.txt

@@ -47,9 +47,8 @@ base-name::
 	<base-name> to determine the name of the created file.
 	When this option is used, the two files are written in
 	<base-name>-<SHA1>.{pack,idx} files.  <SHA1> is a hash
-	of object names (currently in random order so it does
+	of the sorted object names to make the resulting filename
-	not have any useful meaning) to make the resulting
+	based on the pack content, and written to the standard
-	filename reasonably unique, and written to the standard
 	output of the command.
 
 --stdout::