staging: ks7010: avoid one extra level indentation in ks_wlan_hw_rx function

This commit use an and operator in a if condition to avoid one
indentation level which is not needed at all.

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