Staging: vt6655: add missing free_netdev() on error in hostap_enable_hostapd()

Add the missing free_netdev() before return from function
hostap_enable_hostapd() in the error handling case.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>