econet: Do the correct cleanup after an unprivileged SIOCSIFADDR.

We need to drop the mutex and do a dev_put, so set an error code and break like
the other paths, instead of returning directly.
Signed-off-by: NNelson Elhage <nelhage@ksplice.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/econet/af_econet.c

@@ -661,8 +661,10 @@ static int ec_dev_ioctl(struct socket *sock, unsigned int cmd, void __user *arg)
 	err = 0;
 	switch (cmd) {
 	case SIOCSIFADDR:
-		if (!capable(CAP_NET_ADMIN))
-			return -EPERM;
+		if (!capable(CAP_NET_ADMIN)) {
+			err = -EPERM;
+			break;
+		}
 
 		edev = dev->ec_ptr;
 		if (edev == NULL) {