Fix all examples in comments in active_model attribute methods

activemodel/lib/active_model/attribute_methods.rb

@@ -88,7 +88,7 @@ module ClassMethods
       #
       #     attr_accessor :name
       #     attribute_method_prefix 'clear_'
-      #     define_attribute_methods :name
+      #     define_attribute_methods [:name]
       #
       #     private
       #
@@ -124,7 +124,7 @@ def attribute_method_prefix(*prefixes)
       #
       #     attr_accessor :name
       #     attribute_method_suffix '_short?'
-      #     define_attribute_methods :name
+      #     define_attribute_methods [:name]
       #
       #     private
       #
@@ -160,7 +160,7 @@ def attribute_method_suffix(*suffixes)
       #
       #     attr_accessor :name
       #     attribute_method_affix prefix: 'reset_', suffix: '_to_default!'
-      #     define_attribute_methods :name
+      #     define_attribute_methods [:name]
       #
       #     private
       #
@@ -186,7 +186,7 @@ def attribute_method_affix(*affixes)
       #
       #     attr_accessor :name
       #     attribute_method_suffix '_short?'
-      #     define_attribute_methods :name
+      #     define_attribute_methods [:name]
       #
       #     alias_attribute :nickname, :name
       #
@@ -256,7 +256,7 @@ def define_attribute_methods(*attr_names)
       #     # Call to define_attribute_method must appear after the
       #     # attribute_method_prefix, attribute_method_suffix or
       #     # attribute_method_affix declares.
-      #     define_attribute_method :name
+      #     define_attribute_method [:name]
       #
       #     private
       #
@@ -293,7 +293,7 @@ def define_attribute_method(attr_name)
       #
       #     attr_accessor :name
       #     attribute_method_suffix '_short?'
-      #     define_attribute_method :name
+      #     define_attribute_method [:name]
       #
       #     private
       #