cpuidle: use first valid target residency as poll time

Commit 259231a0 ("cpuidle: add poll_limit_ns to cpuidle_device
structure") changed, by mistake, the target residency from the first
available sleep state to the last available sleep state (which should
be longer).

This might cause excessive polling.

Fixes: 259231a0 ("cpuidle: add poll_limit_ns to cpuidle_device structure")
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpuidle/cpuidle.c

@@ -382,6 +382,7 @@ u64 cpuidle_poll_time(struct cpuidle_driver *drv,
 			continue;
 
 		limit_ns = (u64)drv->states[i].target_residency_ns;
+		break;
 	}
 
 	dev->poll_limit_ns = limit_ns;