gitweb: Fix typo in git_difftree_body

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

gitweb/gitweb.perl

@@ -1556,7 +1556,7 @@ sub git_difftree_body {
 			              "blob") .
 			      " | " .
 			      $cgi->a({-href => href(action=>"history", hash_base=>$parent,
-			                             file_name=>$diff{'file'})},\
+			                             file_name=>$diff{'file'})},
 			              "history") .
 			      "</td>\n";