This patch fixes the warning "Using plain integer as NULL pointer",
generated by sparse, by replacing
	if (var == 0)
with
	if (!var)
after an allocation
and all other offending 0s with NULL.

KernelVersion: linus' tree-1f0324caSigned-off-by: NPeter Huewe <peterhuewe@gmx.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>