mm: vmscan: avoid swapping in interrupt context

mm: vmscan: avoid swapping in interrupt context

pages can be swapped out from interrupt context as well.
zram uses zsmalloc allocator to make room for these pages.
But zsmalloc is not made to be used from interrupt context.
This can result in a kernel OOps.

Bug 200063583

Change-Id: Ia74ccbdd5dd9b0713e5e5d170a0c6f0d8b8a895b
Signed-off-by: Sri Krishna chowdary <schowdary@nvidia.com>
Reviewed-on: http://git-master/r/737108
Reviewed-on: http://git-master/r/739416
(cherry picked from commit 204ca8e304a872faa045177c8d9d13bc96e75b86)
Reviewed-on: http://git-master/r/763439
(cherry picked from commit 74185cd61bd30b86c196c4748621877e9b6f8203)
Reviewed-on: http://git-master/r/1159927
GVS: Gerrit_Virtual_Submit
Reviewed-by: Sachin Nikam <snikam@nvidia.com>