[qca-nss-clients] DTLS IPv6 + UDPLite flag masking fix.

The IPv6 + UDPLite path was not getting hit because of invalid
masking. The patch fixes the invalid making.

Signed-off-by: Himanshu Joshi <himajosh@codeaurora.org>
Change-Id: Ib80d1ca274a23d95e0f189517e2ab403bf7d7a75
diff --git a/dtls/v2.0/nss_dtlsmgr_ctx.c b/dtls/v2.0/nss_dtlsmgr_ctx.c
index 19b5188..b8d7da7 100644
--- a/dtls/v2.0/nss_dtlsmgr_ctx.c
+++ b/dtls/v2.0/nss_dtlsmgr_ctx.c
@@ -370,7 +370,7 @@
 	 * to work with dynamically created interfaces
 	 *
 	 */
-	switch (data->flags & NSS_DTLSMGR_HDR_MASK) {
+	switch (data->flags & (NSS_DTLSMGR_HDR_IPV6 | NSS_DTLSMGR_HDR_CAPWAP)) {
 	case NSS_DTLSMGR_HDR_IPV6 | NSS_DTLSMGR_HDR_CAPWAP:
 		data->dest_ifnum = NSS_IPV6_RX_INTERFACE;
 		data->headroom += sizeof(struct ipv6hdr);