[media] drivers/media/usb/{s2255drv.c, tm6000/tm6000-alsa.c, tm6000/tm6000-input.c}: Remove potential NULL dereferences

If the NULL test is necessary, the initialization involving a dereference of
the tested value should be moved after the NULL test.

The sematic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
type T;
expression E;
identifier i,fld;
statement S;
@@

- T i = E->fld;
+ T i;
  ... when != E
      when != i
  if (E == NULL) S
+ i = E->fld;
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/usb/tm6000/tm6000-input.c b/drivers/media/usb/tm6000/tm6000-input.c
index e80b7e1..dffbd4b 100644
--- a/drivers/media/usb/tm6000/tm6000-input.c
+++ b/drivers/media/usb/tm6000/tm6000-input.c
@@ -319,12 +319,13 @@
 static int __tm6000_ir_int_start(struct rc_dev *rc)
 {
 	struct tm6000_IR *ir = rc->priv;
-	struct tm6000_core *dev = ir->dev;
+	struct tm6000_core *dev;
 	int pipe, size;
 	int err = -ENOMEM;
 
 	if (!ir)
 		return -ENODEV;
+	dev = ir->dev;
 
 	dprintk(2, "%s\n",__func__);