ring-buffer: Add enum names for the context levels
ring-buffer: Add enum names for the context levels

Instead of having hard coded numbers for the context levels, use
enums to describe them more.

Signed-off-by: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs