kernel, cpuset: remove exception for __GFP_THISNODE

kernel, cpuset: remove exception for __GFP_THISNODE

Nothing calls __cpuset_node_allowed() with __GFP_THISNODE set anymore, so
remove the obscure comment about it and its special-case exception.

Signed-off-by: David Rientjes <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Pravin Shelar <[email protected]>
Cc: Jarno Rajahalme <[email protected]>
Cc: Li Zefan <[email protected]>
Cc: Greg Thelen <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>