Remove PROP_PATH_SYSTEM_DEFAULT.

Change-Id: Ib01d9c2f9d890eb5e7ba1e15bd11767195e84967
diff --git a/libc/include/sys/_system_properties.h b/libc/include/sys/_system_properties.h
index 44fe991..7ff3ded 100644
--- a/libc/include/sys/_system_properties.h
+++ b/libc/include/sys/_system_properties.h
@@ -80,7 +80,6 @@
 
 #define PROP_PATH_RAMDISK_DEFAULT  "/default.prop"
 #define PROP_PATH_SYSTEM_BUILD     "/system/build.prop"
-#define PROP_PATH_SYSTEM_DEFAULT   "/system/default.prop"
 #define PROP_PATH_VENDOR_BUILD     "/vendor/build.prop"
 #define PROP_PATH_BOOTIMAGE_BUILD  "/build.prop"
 #define PROP_PATH_LOCAL_OVERRIDE   "/data/local.prop"