LP #821709: pt-show-grants --revoke and --separate don't work together

**Reported in Launchpad by Daniel Nichter last update 08-02-2012 15:29:13

Imported from http://code.google.com/p/maatkit/issues/detail?id=1086

Quoting original which also has a patch:

Example output:

GRANT UPDATE ON `mysql`.* TO 'foo'@'%';
REVOKE GRANT UPDATE ON `mysql`.* TO 'foo'@'%' ON `mysql`.* FROM 'foo'@'%';

Should be

REVOKE UPDATE ON `mysql`.* FROM 'foo'@'%';