I_S table columns information is available for any user 


mysql-test/r/information_schema.result:
  Fix for bug#10261: INFORMATION_SCHEMA.COLUMNS, incomplete result for non root user
mysql-test/t/information_schema.test:
  Fix for bug#10261: INFORMATION_SCHEMA.COLUMNS, incomplete result for non root user
sql/sql_show.cc:
  Fix for bug#10261: INFORMATION_SCHEMA.COLUMNS, incomplete result for non root user