fsck,quotacheck: drop support for traditional /forcefsck, /fastboot, and /forcequotac...

fsck,quotacheck: drop support for traditional /forcefsck, /fastboot, and /forcequotacheck files

Instead, please use the kernel command line options with the same name.

I am not sure these files are System V complieant or not, but at least
they are very traditional way to control fsck or quotacheck.
However, the concept of the files are really broken, especially for
fsck. As when we want to fsck the root filesystem, we need to access the
filessystem, but it may be broken...

Let's drop such traditional ways to control fsck and quotacheck.
We already support kernel command line options to control the behaviors.
Maybe, also it is better to provide ways to control them by credentials.