arm64: Move show_unhandled_signals_ratelimited into traps.c

show_unhandled_signals_ratelimited is only called in traps.c, so move it
out of its macro in the dreaded system_misc.h and into a static function
in traps.c

Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 835411ca..b139fe2 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -223,6 +223,13 @@
 		do_exit(SIGSEGV);
 }
 
+static bool show_unhandled_signals_ratelimited(void)
+{
+	static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
+				      DEFAULT_RATELIMIT_BURST);
+	return show_unhandled_signals && __ratelimit(&rs);
+}
+
 void arm64_force_sig_info(struct siginfo *info, const char *str,
 			  struct task_struct *tsk)
 {