mwifiex: Mark expected switch fall-through

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/mwifiex/ie.c

@@ -363,6 +363,7 @@ static int mwifiex_uap_parse_tail_ies(struct mwifiex_private *priv,
 						    (const u8 *)hdr,
 						    hdr->len + sizeof(struct ieee_types_header)))
 				break;
+			/* fall through */
 		default:
 			memcpy(gen_ie->ie_buffer + ie_len, hdr,
 			       hdr->len + sizeof(struct ieee_types_header));