In each case, error codes are stored in ret, but the return value is always
0.  Return ret 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: NJulia Lawall <julia@diku.dk>
Acked-by: NKalle Valo <kvalo@adurom.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>