Convert a nonnegative error return code to a negative one, as returned
elsewhere in the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>
Signed-off-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch adds support to the PCAN-PC Card PCMCIA card from
PEAK-System Technik (www.peak-system.com). This card is a CAN interface
for the PC Card slot. It is available as a single or dual-channel version.
Tested-by: NOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>