kprobes: check CONFIG_FREEZER instead of CONFIG_PM

Check CONFIG_FREEZER instead of CONFIG_PM because kprobe booster
depends on freeze_processes() and thaw_processes() when CONFIG_PREEMPT=y.

This fixes a linkage error which occurs when CONFIG_PREEMPT=y, CONFIG_PM=y
and CONFIG_FREEZER=n.

Reported-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 1b9cbdc..7ba8cd9 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -123,7 +123,7 @@
 static int __kprobes check_safety(void)
 {
 	int ret = 0;
-#if defined(CONFIG_PREEMPT) && defined(CONFIG_PM)
+#if defined(CONFIG_PREEMPT) && defined(CONFIG_FREEZER)
 	ret = freeze_processes();
 	if (ret == 0) {
 		struct task_struct *p, *q;