Fix build breakage for missing -Wcpp option on old GCC versions.

Bug: 14416410
Change-Id: Ib30c3739d50d6122b3b4643051c72f2fa4985686
diff --git a/Android.mk b/Android.mk
index 3643aa5..138e747 100644
--- a/Android.mk
+++ b/Android.mk
@@ -72,7 +72,10 @@
   LOCAL_SRC_FILES += fdevent.c
 endif
 
-LOCAL_CFLAGS += -O2 -g -DADB_HOST=1 -Wall -Wno-unused-parameter -Wno-error=cpp -Werror
+LOCAL_CFLAGS += -O2 -g -DADB_HOST=1 -Wall -Wno-unused-parameter -Werror
+ifeq ($(HOST_OS),windows)
+LOCAL_CFLAGS += -Wno-error=cpp
+endif
 LOCAL_CFLAGS += -D_XOPEN_SOURCE -D_GNU_SOURCE
 LOCAL_MODULE := adb
 LOCAL_MODULE_TAGS := debug