[nrf noup] zephyr: Fix handling of zero-byte receive

fixup! [nrf noup] zephyr: Add support for WPA CLI zephyr

Sometimes even if the peer didn't close the socket, we still see zero
byte receive, and un-registering for those cases causes the system to
be broken.

Handle the case by ignoring the current message but keeping the socket
registered.

Fixes SHEL-2283.

Signed-off-by: Chaitanya Tata <[email protected]>

wpa_supplicant/ctrl_iface_zephyr.c

@@ -148,7 +148,6 @@ static void wpa_supplicant_ctrl_iface_receive(int sock, void *eloop_ctx,
 		return;
 	}
 	if (!res) {
-		eloop_unregister_sock(sock, EVENT_TYPE_READ);
 		wpa_printf(MSG_DEBUG, "ctrl_iface: Peer unexpectedly shut down "
 			   "socket");
 		os_free(buf);