Fix example in git-name-rev documentation

Since 59d3f54 (name-rev: avoid "^0" when unneeded, 2007-02-20), name-rev
stopped showing an unnecessary "^0" to dereference a tag down to a commit.
The patch should have made a matching update to the documentation, but we
forgot.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-name-rev.txt

@@ -59,7 +59,7 @@ Enter 'git-name-rev':
 
 ------------
 % git name-rev 33db5f4d9027a10e477ccf054b2c1ab94f74c85a
-33db5f4d9027a10e477ccf054b2c1ab94f74c85a tags/v0.99^0~940
+33db5f4d9027a10e477ccf054b2c1ab94f74c85a tags/v0.99~940
 ------------
 
 Now you are wiser, because you know that it happened 940 revisions before v0.99.