Documentation: update cgroups info user groups names

Update suitable words to explain / understand cgroups contents.

Signed-off-by: Geunsik Lim <[email protected]>
Cc: Paul Menage <[email protected]>
Signed-off-by: Randy Dunlap <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
1 file changed