Documentation: gitrevisions is in section 7

Fix references to gitrevisions(1) in the manual pages and HTML
documentation.

In practice, this will not matter much unless someone tries to use a
hard copy of the git reference manual.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/git.txt b/Documentation/git.txt
index dd57bdc..b46c6f6 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -495,7 +495,7 @@
 	(i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 
 For a more complete list of ways to spell object names, see
-"SPECIFYING REVISIONS" section in linkgit:gitrevisions[1].
+"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
 
 
 File/Directory Structure