make suggested changes to comments and augopen

lib/puppet/provider/pam/augeas.rb

@@ -52,23 +52,25 @@ def self.position_path (position, type)
       expr = PAM_POSITION_ALIASES[key][identifier]
       expr = key ? expr % [type, value] : expr % [type]
     else
+      # if the identifier is not in the mapping
+      # we assume that its an xpath and so
+      # join everything after the placement
       expr = position.split(/ /)[1..-1].join(" ")
     end
     return expr, placement
   end
 
   def in_position?
     unless resource[:position].nil?
-      aug = nil
       path, before = self.class.position_path(resource[:position], resource[:type])
 
-      augopen do |aug|
-        if before == 'before'
-          mpath = "#{resource_path}[following-sibling::#{path}]"
-        else
-          mpath = "#{resource_path}[preceding-sibling::#{path}]"
-        end
+      if before == 'before'
+        mpath = "#{resource_path}[following-sibling::#{path}]"
+      else
+        mpath = "#{resource_path}[preceding-sibling::#{path}]"
+      end
 
+      augopen do |aug|
         !aug.match(mpath).empty?
       end
     end