[fixlet] mm/vmpressure: skip tree=true accounting on cgroup v2

[Usama Arif]

Simplify the guard. Both cgroup_subsys_on_dfl() and tree are bool, so
the two combinations that have no consumer (v1 + tree=false, v2 +
tree=true) are exactly the cases where dfl == tree.

Suggested-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Usama Arif <usama.arif@xxxxxxxxx>
---
 mm/vmpressure.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index 14470141bbe6..9629240d77ad 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -120,8 +120,7 @@ void vmpressure(gfp_t gfp, int order, struct mem_cgroup *memcg, bool tree,
 	 *   cgroup v1 + tree=true  -> userspace eventfds (memory.pressure_level)
 	 * Skip the other two: nothing consumes the result.
 	 */
-	if ((!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !tree) ||
-	    (cgroup_subsys_on_dfl(memory_cgrp_subsys) && tree))
+	if (cgroup_subsys_on_dfl(memory_cgrp_subsys) == tree)
 		return;
 
 	vmpr = memcg_to_vmpressure(memcg);
-- 
2.53.0-Meta