stack tracer: depends on DEBUG_KERNEL

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 2a22e46..5a9cffb 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -109,6 +109,7 @@
 config STACK_TRACER
 	bool "Trace max stack"
 	depends on HAVE_FTRACE
+	depends on DEBUG_KERNEL
 	select FTRACE
 	select STACKTRACE
 	help