[qca-nss-drv] Fix compile errors when debug is turned on

Fixes some compile time issues seen when driver debug is turned on

Change-Id: Iec6d7d01ee9cffc160c87d116cf946833db4c4ac
Signed-off-by: Sakthi Vignesh Radhakrishnan <sradhakr@codeaurora.org>
diff --git a/nss_tun6rd.c b/nss_tun6rd.c
index 784a922..ad76eb3 100644
--- a/nss_tun6rd.c
+++ b/nss_tun6rd.c
@@ -182,7 +182,7 @@
  */
 void nss_unregister_tun6rd_if(uint32_t if_num)
 {
-	nss_assert(nss_is_dynamic_interface(ncm->interface));
+	nss_assert(nss_is_dynamic_interface(if_num));
 
 	nss_top_main.subsys_dp_register[if_num].ndev = NULL;
 	nss_top_main.subsys_dp_register[if_num].cb = NULL;