kdd: build using Werror

We build most of tools using Werror and there seems to be no
deliberate reason for this to be an exception.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Tim Deegan <tim@xen.org>

tools/debugger/kdd/Makefile

@@ -1,6 +1,7 @@
 XEN_ROOT = $(CURDIR)/../../..
 include $(XEN_ROOT)/tools/Rules.mk
 
+CFLAGS  += -Werror
 CFLAGS  += $(CFLAGS_libxenctrl)
 CFLAGS  += -DXC_WANT_COMPAT_MAP_FOREIGN_API
 LDLIBS  += $(LDLIBS_libxenctrl)