Documentation: fix links to tutorials and other new manual pages

With the conversion of HTML documentation to man pages

tutorial.html -> gittutorial (7)
tutorial-2.html -> gittutorial-2 (7)
cvs-migration.html -> gitcvs-migration (7)
diffcore.html -> gitdiffcore (7)
repository-layout.html -> gitrepository-layout (5)
hooks.html -> githooks (5)
glossary.html -> gitglossary (7)
core-tutorial.html -> gitcore-tutorial (7)

and the automatic update of references to these pages,
a little debris was left behind. We clear it away.

Signed-off-by: Jonathan Nieder <jrnieder@uchicago.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index d0fe192..656d4db 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -97,7 +97,7 @@
 -n::
 --no-verify::
 	This option bypasses the pre-commit and commit-msg hooks.
-	See also linkgit:githooks[5][hooks].
+	See also linkgit:githooks[5].
 
 --allow-empty::
 	Usually recording a commit that has the exact same tree as its
@@ -316,7 +316,7 @@
 HOOKS
 -----
 This command can run `commit-msg`, `prepare-commit-msg`, `pre-commit`,
-and `post-commit` hooks.  See linkgit:githooks[5][hooks] for more
+and `post-commit` hooks.  See linkgit:githooks[5] for more
 information.