video: udlfb: Use NULL instead of 0

new_back is a pointer. Use NULL instead of 0.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/udlfb.c b/drivers/video/udlfb.c
index d2e5bc3..025f14e 100644
--- a/drivers/video/udlfb.c
+++ b/drivers/video/udlfb.c
@@ -1166,7 +1166,7 @@
 	int new_len;
 	unsigned char *old_fb = info->screen_base;
 	unsigned char *new_fb;
-	unsigned char *new_back = 0;
+	unsigned char *new_back = NULL;
 
 	pr_warn("Reallocating framebuffer. Addresses will change!\n");