sched: Remove duplicated tick_nohz_full_enabled() check

In sched_update_tick_dependency() there's two calls that check
whether nohz_full is enabled: tick_nohz_full_cpu() does it
implicitly, while there's also an explicit call to tick_nohz_full_enabled().

Remove the duplicated, open coded check.

[ mingo: Amended the changelog. ]
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/1595935075-14223-1-git-send-email-linmiaohe@huawei.com

kernel/sched/sched.h

@@ -1961,12 +1961,7 @@ extern int __init sched_tick_offload_init(void);
  */
 static inline void sched_update_tick_dependency(struct rq *rq)
 {
-	int cpu;
-
-	if (!tick_nohz_full_enabled())
-		return;
-
-	cpu = cpu_of(rq);
+	int cpu = cpu_of(rq);
 
 	if (!tick_nohz_full_cpu(cpu))
 		return;