commit a816e311 upstream.

Pointers should not be compared to plain integers.
Quiets the sparse warning:
warning: Using plain integer as NULL pointer
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>