Use "module_function def foo(args)" instead separating them

with an empty line like Rubocop wants.

src/ruby/yast/logger.rb

@@ -2,10 +2,8 @@
 require "yast/builtins"
 
 module Yast
-  module_function
-
   # @private
-  def y2_logger_helper(level, args)
+  module_function def y2_logger_helper(level, args)
     caller_frame = 1
     backtrace = false
 
@@ -31,46 +29,34 @@ def y2_logger_helper(level, args)
     end
   end
 
-  module_function
-
   # write to log debug message with arguments formated by {Yast::Builtins.sformat}
-  def y2debug(*args)
+  module_function def y2debug(*args)
     y2_logger_helper(0, args)
   end
 
-  module_function
-
   # write to log milestone message with arguments formated by {Yast::Builtins.sformat}
-  def y2milestone(*args)
+  module_function def y2milestone(*args)
     y2_logger_helper(1, args)
   end
 
-  module_function
-
   # write to log warning message with arguments formated by {Yast::Builtins.sformat}
-  def y2warning(*args)
+  module_function def y2warning(*args)
     y2_logger_helper(2, args)
   end
 
-  module_function
-
   # write to log error message with arguments formated by {Yast::Builtins.sformat}
-  def y2error(*args)
+  module_function def y2error(*args)
     y2_logger_helper(3, args)
   end
 
-  module_function
-
   # write to log security message with arguments formated by {Yast::Builtins.sformat}
   # @todo make it clear what is supposed to write to this level
-  def y2security(*args)
+  module_function def y2security(*args)
     y2_logger_helper(4, args)
   end
 
-  module_function
-
   # write to log internal error message with arguments formated by {Yast::Builtins.sformat}
-  def y2internal(*args)
+  module_function def y2internal(*args)
     y2_logger_helper(5, args)
   end
 end # module YaST