staging: vt6656: check ieee80211_bss_conf bssid not NULL
staging: vt6656: check ieee80211_bss_conf bssid not NULL

Sometimes bssid can go null on failed association.

Signed-off-by: Malcolm Priestley <123fd39c698f702285d09eaebae85efdff081c95@gmail.com>
Cc: <4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org> # v3.17+
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs