test_vector.rb: fix exception class

* test/matrix/test_vector.rb (test_independent): fix exception
  class path, Vector does not have its own TypeError.  [#10451]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48509 b2dd03c8-39d4-4d8f-98ff-823fe69b080e