V4L/DVB: drivers/media: Use available error codes

In each case, error codes are stored in rc, but the return value is always
0.  Return rc instead.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
local idexpression x;
constant C;
@@

if (...) { ...
  x = -C
  ... when != x
(
  return <+...x...+>;
|
  return NULL;
|
  return;
|
* return ...;
)
}
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/frontends/drx397xD.c

@@ -232,7 +232,7 @@ static int write_fw(struct drx397xD_state *s, enum blob_ix ix)
 exit_rc:
 	read_unlock(&fw[s->chip_rev].lock);
 
-	return 0;
+	return rc;
 }
 
 /* Function is not endian safe, use the RD16 wrapper below */

drivers/media/video/s2255drv.c

@@ -600,7 +600,7 @@ static int s2255_got_frame(struct s2255_channel *channel, int jpgsize)
 	dprintk(2, "%s: [buf/i] [%p/%d]\n", __func__, buf, buf->vb.i);
 unlock:
 	spin_unlock_irqrestore(&dev->slock, flags);
-	return 0;
+	return rc;
 }
 
 static const struct s2255_fmt *format_by_fourcc(int fourcc)