package/hostapd: fix crash in atheros driver (#8143)...

package/hostapd: fix crash in atheros driver (#8143) hapd->driver->set_operstate may happen when the drv_priv data is not initialized yet, this leads to a null pointer deref in the atheros driver. Protect the operstate call with a check for hapd->drv_priv.

SVN-Revision: 23715