Fix build error on 4.4 kernel.

Change-Id: Ibe9c793dd4e1fbf36717c6769a36b615edd734a1
diff --git a/debian/rules b/debian/rules
index 4ebe98c..f325f00 100755
--- a/debian/rules
+++ b/debian/rules
@@ -8,6 +8,8 @@
 DESTDIR=$(shell pwd)/debian/$(PACKAGENAME)
 CURDIR=$(shell pwd)
 
+LDFLAGS := -z relro
+
 DESTDIR=$(shell pwd)/debian/$(PACKAGENAME)
 CURDIR=$(shell pwd)
 KERNELVERSION=4.4.22-mtk