init: fix copying boot properties

The previous patch "init: verify size of property buffers passed
to property_get" incorrectly modified one of the callers,
resulting in ro.serialno, ro.bootmode, ro.baseband, and
ro.bootloader always being set to their default values.

Bug: 9469860

(cherry picked from commit 67e3663fc9)

Change-Id: Ia7b337e1fab6e334729f47ee1269e6c736615177

init/init.c

@@ -640,7 +640,9 @@ static void export_kernel_boot_props(void)
 
     for (i = 0; i < ARRAY_SIZE(prop_map); i++) {
         ret = property_get(prop_map[i].src_prop, tmp);
-        if (ret == 0)
+        if (ret > 0)
+            property_set(prop_map[i].dest_prop, tmp);
+        else
             property_set(prop_map[i].dest_prop, prop_map[i].def_val);
     }