sh: stacktrace: Add reliability checks in address saving ops.

This adopts the reliability checks from the x86 stacktrace code so known
bad addresses are not recorded in the stack trace buffer.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/stacktrace.c

@@ -38,6 +38,9 @@ static void save_stack_address(void *data, unsigned long addr, int reliable)
 {
 	struct stack_trace *trace = data;
 
+	if (!reliable)
+		return;
+
 	if (trace->skip > 0) {
 		trace->skip--;
 		return;
@@ -67,6 +70,9 @@ save_stack_address_nosched(void *data, unsigned long addr, int reliable)
 {
 	struct stack_trace *trace = (struct stack_trace *)data;
 
+	if (!reliable)
+		return;
+
 	if (in_sched_functions(addr))
 		return;