修改sn获取方式

Signed-off-by: Nlaiguizhong <laiguizhong@huawei.com>

interfaces/innerkits/syspara/parameter.c

@@ -231,8 +231,13 @@ const char *GetBuildTime(void)
 
 const char *GetSerial(void)
 {
-    static const char *ohos_serial = NULL;
-    return GetProperty("ohos.boot.sn", &ohos_serial);
+    static const char ohos_serial[PARAM_VALUE_LEN_MAX]  = {0};
+    uint32_t len = PARAM_VALUE_LEN_MAX;
+    int ret = SystemGetParameter("ohos.boot.sn", ohos_serial, &len); 
+    if (ret != 0) {
+        return NULL;
+    }
+    return ohos_serial;
 }
 
 int GetDevUdid(char *udid, int size)