[qca-nss-clients] Fix invalid pointer typecast for callback_t in msg_init APIs

msg_init() APIs don't need a typecast for callbacks. Fix the invalid typecast
for all the callbacks in msg_init.

Change-Id: Ie622d264d2da0a6932be985bac1c888c37312f14
Signed-off-by: Sundarajan Srinivasan <sundaraj@codeaurora.org>
diff --git a/nss_ipsecmgr.c b/nss_ipsecmgr.c
index fcd50ee..be68150 100644
--- a/nss_ipsecmgr.c
+++ b/nss_ipsecmgr.c
@@ -733,7 +733,7 @@
 
 	nim->tunnel_id = dev->ifindex;
 
-	nss_ipsec_msg_init(nim, if_num, type, NSS_IPSEC_MSG_LEN, (nss_ipsec_msg_callback_t *)nss_ipsecmgr_op_receive, dev);
+	nss_ipsec_msg_init(nim, if_num, type, NSS_IPSEC_MSG_LEN, nss_ipsecmgr_op_receive, dev);
 
 	status = nss_ipsec_tx_msg(priv->nss_ctx, nim);
 	if (status != NSS_TX_SUCCESS) {