mm: vmscan: If kswapd has been running too long, allow it to sleep

Under constant allocation pressure, kswapd can be in the situation where
sleeping_prematurely() will always return true even if kswapd has been
running a long time. Check if kswapd needs to be scheduled.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Revert "mm: vmscan: when kswapd is awoken due to reclaim by a running task"

This reverts commit e507a4ddd500da4ac6128f393f4ad7fbaaa48a42.
fix smartmax