converting inject to each and map

[#4119 state:committed]
Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

activerecord/lib/active_record/base.rb

@@ -2001,10 +2001,9 @@ def attributes=(new_attributes, guard_protected_attributes = true)
 
       # Returns a hash of all the attributes with their names as keys and the values of the attributes as values.
       def attributes
-        self.attribute_names.inject({}) do |attrs, name|
-          attrs[name] = read_attribute(name)
-          attrs
-        end
+        attrs = {}
+        attribute_names.each { |name| attrs[name] = read_attribute(name) }
+        attrs
       end
 
       # Returns an <tt>#inspect</tt>-like string for the value of the
@@ -2348,7 +2347,7 @@ def find_parameter_position(multiparameter_name)
 
       # Returns a comma-separated pair list, like "key1 = val1, key2 = val2".
       def comma_pair_list(hash)
-        hash.inject([]) { |list, pair| list << "#{pair.first} = #{pair.last}" }.join(", ")
+        hash.map { |k,v| "#{k} = #{v}" }.join(", ")
       end
 
       def quote_columns(quoter, hash)