mm/memcontrol: fix typo in comment

Replace 'then' with 'than'.

Link: https://lkml.kernel.org/r/20230522095233.4246-1-haifeng.xu@shopee.com
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memcontrol.c

@@ -6862,7 +6862,7 @@ static unsigned long effective_protection(unsigned long usage,
 	protected = min(usage, setting);
 	/*
 	 * If all cgroups at this level combined claim and use more
-	 * protection then what the parent affords them, distribute
+	 * protection than what the parent affords them, distribute
 	 * shares in proportion to utilization.
 	 *
 	 * We are using actual utilization rather than the statically