sched/numa: Document vma_numab_state fields

[ Upstream commit 9ae5c00e ]

Document the intended usage of the fields.

[ mingo: Reformatted to take less vertical space & tidied it up. ]

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20231010083143.19593-2-mgorman@techsingularity.net


Stable-dep-of: f22cde43 ("sched/numa: Fix the vma scan starving issue")
Signed-off-by: Sasha Levin <sashal@kernel.org>