FT: Set WLAN_AUTH_FT auth_alg on FT-over-DS case

This is needed to allow reassociation processing to skip 4-way handshake
when FT-over-DS is used with an AP that has a previous association state
with the STA.

src/ap/wpa_auth_glue.c

@@ -349,8 +349,10 @@ hostapd_wpa_auth_add_sta(void *ctx, const u8 *sta_addr)
 	sta = ap_sta_add(hapd, sta_addr);
 	if (sta == NULL)
 		return NULL;
-	if (sta->wpa_sm)
+	if (sta->wpa_sm) {
+		sta->auth_alg = WLAN_AUTH_FT;
 		return sta->wpa_sm;
+	}
 
 	sta->wpa_sm = wpa_auth_sta_init(hapd->wpa_auth, sta->addr);
 	if (sta->wpa_sm == NULL) {