gitweb: Fix "next" link in commit view

Fix copy'n'paste error in commit c9d193d which caused that "next"
link for merge commits in "commit" view
  (merge: _commit_ _commit_ ...)
was to "commitdiff" view instead of being to "commit" view.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

gitweb/gitweb.perl

@@ -3719,7 +3719,7 @@ sub git_commit {
 		$formats_nav .=
 			'(merge: ' .
 			join(' ', map {
-				$cgi->a({-href => href(action=>"commitdiff",
+				$cgi->a({-href => href(action=>"commit",
 				                       hash=>$_)},
 				        esc_html(substr($_, 0, 7)));
 			} @$parents ) .