simple_lmk: Ratelimit the 'no processes available to kill' message

Under extreme simulated memory pressure, the 'no processes available to
kill' message can be spammed hundreds of thousands of times, which is not
productive. Ratelimit it.

Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>

drivers/android/simple_lmk.c

@@ -10,6 +10,7 @@
 #include <linux/mm.h>
 #include <linux/moduleparam.h>
 #include <linux/oom.h>
+#include <linux/ratelimit.h>
 #include <linux/sort.h>
 #include <linux/vmpressure.h>
 #include <uapi/linux/sched/types.h>
@@ -193,7 +194,7 @@ static void scan_and_kill(void)
 	/* Populate the victims array with tasks sorted by adj and then size */
 	pages_found = find_victims(&nr_found);
 	if (unlikely(!nr_found)) {
-		pr_err("No processes available to kill!\n");
+		pr_err_ratelimited("No processes available to kill!\n");
 		return;
 	}