[PATCH] dvb: fix NULL pointer dereference when loading the budget-av module

Ralph Metzler wrote:
> AFAIR, there is a bug in tda10021.c in tda10021_readreg() which
> references state->frontend.dvb->num
> This is fatal if the frontend is not at the probed address and thus
> not yet registered (no dvb entry set yet -> NULL pointer ...).

The attached patch should get rid of the oops.

Signed-off-by: Jon Burgess <jburgess@uklinux.net>
Cc: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/media/dvb/frontends/tda10021.c

@@ -100,8 +100,8 @@ static u8 tda10021_readreg (struct tda10021_state* state, u8 reg)
 
 	ret = i2c_transfer (state->i2c, msg, 2);
 	if (ret != 2)
-		printk("DVB: TDA10021(%d): %s: readreg error (ret == %i)\n",
-				state->frontend.dvb->num, __FUNCTION__, ret);
+		printk("DVB: TDA10021: %s: readreg error (ret == %i)\n",
+				__FUNCTION__, ret);
 	return b1[0];
 }