解决87157

Change-Id: Iaa3a183d52eed338de68fdfba92992723094c56f
diff --git a/mbtk/mbtk_rild/src/mbtk_data_call.c b/mbtk/mbtk_rild/src/mbtk_data_call.c
index 321fb7c..cc1488d 100755
--- a/mbtk/mbtk_rild/src/mbtk_data_call.c
+++ b/mbtk/mbtk_rild/src/mbtk_data_call.c
@@ -399,7 +399,7 @@
     property_set(MBTK_APN_STATE, (char *)apn_set_state);
 
     sprintf(buff, "%s%d", MBTK_APN_TYPE, cid);
-    property_set(buff, "NULL");
+    property_set(buff, "");
 
     memset(&apninfo_s[cid], 0x0, sizeof(mbtk_qser_apn_info_s));
     return MBTK_RESULT_SUCCESS;