staging: ks7010: do not dereference priv if priv is null

priv is being dereferenced before a check for it being null
is made, so there is a possibililty a null pointer deference
can occur. Instead, only dereference priv if it is non-null.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>