Man page add remove option spacewalk data fsck

This pull request adds the funcionality on spacewalk-data-fsck to remove the RPM which does not match checksum. 

The second commit adds on spacewalk-data-fsck man page the explanation about the new option. 

Note: this patch have the suggestion proposed by skoty-tkasparek at https://github.com/spacewalkproject/spacewalk/pull/32

Thanks.