staging: wlan-ng: prism2: remove more duplicated #include

Removed duplicated #include "version.h" in
drivers/staging/wlan-ng/p80211wep.c.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>