Remove meaningless default action name

Remove meaningless default action name

Before: Get the value of the action=... parameter. If it's undefined
return 'view'. Check if 'view' equals 'ajax'.

After: Get the value of the action=... parameter. If it's undefined
return null. Check if null equals 'ajax'.

Same for both places. The default value 'view' is never used.

Change-Id: I56656218cfb895bffe886919c67ebf3b79d91515