mesh: Fix peer link counting when removing a mesh peer

When removing a mesh peer with control interface commands (ACCEPT_ACL
DEL_MAC/DENY_ACL ADD_MAC/MESH_PEER_REMOVE) the plink count was not
decreased from its last connection. This resulted in peer link count
leakage and wpa_supplicant rejecting the connections after reaching
max_peer_links (default: 99).

Fix this by decreasing the plink count when removing a mesh peer which
is in PLINK_ESTAB state.

Signed-off-by: Yu Wang <yyuwang@codeaurora.org>

wpa_supplicant/mesh_mpm.c

@@ -533,6 +533,8 @@ static int mesh_mpm_plink_close(struct hostapd_data *hapd, struct sta_info *sta,
 	int reason = WLAN_REASON_MESH_PEERING_CANCELLED;
 
 	if (sta) {
+		if (sta->plink_state == PLINK_ESTAB)
+			hapd->num_plinks--;
 		wpa_mesh_set_plink_state(wpa_s, sta, PLINK_HOLDING);
 		mesh_mpm_send_plink_action(wpa_s, sta, PLINK_CLOSE, reason);
 		wpa_printf(MSG_DEBUG, "MPM closing plink sta=" MACSTR,