[media] video/saa7164: Fix sparse warning: Using plain integer as NULL pointer

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-1f0324c

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/saa7164/saa7164-fw.c b/drivers/media/video/saa7164/saa7164-fw.c
index ebed6f7..b369300 100644
--- a/drivers/media/video/saa7164/saa7164-fw.c
+++ b/drivers/media/video/saa7164/saa7164-fw.c
@@ -88,7 +88,7 @@
 		"%s(image=%p, size=%d, flags=0x%x, dst=%p, dstsize=0x%x)\n",
 		__func__, src, srcsize, dlflags, dst, dstsize);
 
-	if ((src == 0) || (dst == 0)) {
+	if ((src == NULL) || (dst == NULL)) {
 		ret = -EIO;
 		goto out;
 	}