staging: ks7010: change local variable type in ks_wlan_hw_rx

Local variable event in ks_wlan_hw_rx function is declared
as unsigned short and can be declared as u16 which is preferred
style.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>