Changed end-space comparison so that the key is not used past
its end. This is due to the new end-space behaviour in 4.1.
See also bug 6151 and 9188.


mysql-test/r/key.result:
  Bug#12565 - ERROR 1034 when running simple UPDATE or DELETE on large MyISAM table
  The test result.
mysql-test/t/key.test:
  Bug#12565 - ERROR 1034 when running simple UPDATE or DELETE on large MyISAM table
  The test case.