Improved lamba name per @segiddins' comment

https://github.com/CocoaPods/CocoaPods/pull/5927#discussion_r80047314

lib/cocoapods/sandbox/path_list.rb

@@ -57,7 +57,7 @@ module Pod
         dirs, files = dirs_and_files.partition { |path| File.directory?(path) }
 
         root_length = root.cleanpath.to_s.length + File::SEPARATOR.length
-        relative_sorted = lambda do |paths|
+        sorted_relative_paths_from_full_paths = lambda do |paths|
           relative_paths = paths.lazy.map do |path|
             path_string = path.to_s
             path_string.slice(root_length, path_string.length - root_length)
@@ -65,8 +65,8 @@ module Pod
           relative_paths.sort_by(&:upcase)
         end
 
-        @dirs = relative_sorted.call(dirs)
-        @files = relative_sorted.call(files)
+        @dirs = sorted_relative_paths_from_full_paths.call(dirs)
+        @files = sorted_relative_paths_from_full_paths.call(files)
         @glob_cache = {}
       end