Fix code style issues reported by @alloy

lib/cocoapods/target.rb

@@ -81,7 +81,7 @@ module Pod
     # =>                       (e g per build configuration), provide the variant type here.
     # @return [Pathname] the absolute path of the xcconfig file.
     #
-    def xcconfig_path variant
+    def xcconfig_path(variant)
       if variant then
         support_files_root + "#{label}.#{variant}.xcconfig"
       else

lib/cocoapods/target/aggregate_target.rb

@@ -96,8 +96,8 @@ module Pod
     # @return [String] The path of the xcconfig file relative to the root of
     #         the user project.
     #
-    def xcconfig_relative_path config_name
-      relative_to_srcroot(xcconfig_path config_name).to_s
+    def xcconfig_relative_path(config_name)
+      relative_to_srcroot(xcconfig_path(config_name)).to_s
     end
 
     # @return [String] The path of the copy resources script relative to the