Staging: rc2860: return -EFAULT on copy_to_user errors

copy_to_user() returns the number of bytes remaining but we want to
return a negative error code.  This is in the ioctl handler and the
error code gets passed to userspace.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/rt2860/sta_ioctl.c

@@ -2522,6 +2522,8 @@ int rt28xx_sta_ioctl(IN struct net_device *net_dev,
 			Status =
 			    copy_to_user(erq->pointer, pAd->nickname,
 					 erq->length);
+			if (Status)
+				Status = -EFAULT;
 			break;
 		}
 	case SIOCGIWRATE:	/*get default bit rate (bps) */