allowed unintended overflows. (Bug #10351)


mysql-test/r/select_safe.result:
  Update results
mysql-test/r/variables.result:
  Update results
mysql-test/t/select_safe.test:
  Remove "SELECT @@MAX_SEEKS_FOR_KEY;" because it depends on
  size of unsigned long of the system.
mysql-test/t/variables.test:
  Fix test for #10351 to test the actual problem
sql/mysqld.cc:
  Undo unnecessary change to default and max of max_seeks_for_key
sql/set_var.cc:
  On platforms where SIZEOF_LONG != SIZEOF_LONGLONG, make sure to handle
  max values for ulong-sized options correctly.