scm: mercurial: simplify fixing exception operation in adapter "summary" method (#4455).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@4878 e93f8b46-1217-0410-a6f0-8f06a7374b81

lib/redmine/scm/adapters/mercurial_adapter.rb

@@ -113,13 +113,11 @@ module Redmine
           return @summary if @summary 
           doc = nil
           hg 'rhsummary' do |io|
-            output = io.read
             begin
-              doc = ActiveSupport::XmlMini.parse(output)['rhsummary']
+              @summary = ActiveSupport::XmlMini.parse(io.read)['rhsummary']
             rescue
             end
           end
-          @summary = doc
         end
         private :summary