enlarge get_string_simple buffer to 1024 byte.
enlarge get_string_simple buffer to 1024 byte.


git-svn-id: aa7d12129933e08112283aab9207b8956eaf5454@391 0ecacc03-ac1b-0410-941d-e442c79421a6

akr/ruby-usb,akr/ruby-usb