Change httpd Keystone access log to keystone_access.log

Keystone's access log was going to httpd/access.log, which is the
common place for all access logging. This made it difficult to see
Keystone accesses apart from other access. Keystone's access log
will now be keystone_access.log

This makes the Keystone configuration similar to Horizon which uses
horizon_access.log.

Change-Id: I6e5ac121302b3d138758e6c49dffa9f05ad2fb85
Partial-Bug: #1359995
diff --git a/files/apache-keystone.template b/files/apache-keystone.template
index a9d9cc3..f19481e 100644
--- a/files/apache-keystone.template
+++ b/files/apache-keystone.template
@@ -7,7 +7,7 @@
     WSGIScriptAlias / %PUBLICWSGI%
     WSGIApplicationGroup %{GLOBAL}
     ErrorLog /var/log/%APACHE_NAME%/keystone.log
-    CustomLog /var/log/%APACHE_NAME%/access.log combined
+    CustomLog /var/log/%APACHE_NAME%/keystone_access.log combined
 </VirtualHost>
 
 <VirtualHost *:%ADMINPORT%>
@@ -16,7 +16,7 @@
     WSGIScriptAlias / %ADMINWSGI%
     WSGIApplicationGroup %{GLOBAL}
     ErrorLog /var/log/%APACHE_NAME%/keystone.log
-    CustomLog /var/log/%APACHE_NAME%/access.log combined
+    CustomLog /var/log/%APACHE_NAME%/keystone_access.log combined
 </VirtualHost>
 
 # Workaround for missing path on RHEL6, see