Fix rubocop violations

Author: peterzhu2118

test/rubygems/test_gem_platform.rb

@@ -85,8 +85,8 @@ def test_self_new
 
   def test_initialize
     test_cases = {
-      "amd64-freebsd6" => ["amd64",     "freebsd", "6"],
-      "java" => [nil,         "java", nil],
+      "amd64-freebsd6" => ["amd64", "freebsd", "6"],
+      "java" => [nil, "java", nil],
       "jruby" => [nil, "java", nil],
       "universal-dotnet" => ["universal", "dotnet", nil],
       "universal-dotnet2.0" => ["universal", "dotnet",  "2.0"],