Fix same apn change error

Change-Id: I8d505efbdcfb18be8b74a32663179fb07a11dea4
diff --git a/mbtk/mbtk_rild_v2/src/ril_data_call.c b/mbtk/mbtk_rild_v2/src/ril_data_call.c
index 6b1bfe1..ef751ee 100755
--- a/mbtk/mbtk_rild_v2/src/ril_data_call.c
+++ b/mbtk/mbtk_rild_v2/src/ril_data_call.c
@@ -488,9 +488,9 @@
                         LOGW("APN : %s/%s exist, can't add.", apn->apn, apn->type);
                         return -1;
                     } else { // Is change, not change apn name/type to other cid.
-                        if(index != apn->cid) {
+                        if(apns.apns[index].cid != apn->cid) {
                             LOGW("APN : %s/%s exist in cid[%d], can't change to cid[%d]", apn->apn, apn->type,
-                                index, apn->cid);
+                                apns.apns[index].cid, apn->cid);
                             return -1;
                         }
                     }