orinoco: release BSS structures returned by cfg80211_inform_bss()

The pointer returned by cfg80211_inform_bss is a referenced
struct. The orinoco driver does not need to keep the struct, so
we just release it.

Signed-off-by: David Kilroy <kilroyd@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>