PCMCIA: resource, fix lock imbalance

Stanse found that one error path (when alloc_skb fails) in netdev_tx
omits to unlock hw_priv->hwlock. Fix that by moving away from unlock in
each fail path. Unlock at one place instead.

Introduced in 94a819f802
(pcmcia: assert locking to struct pcmcia_device)

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

drivers/pcmcia/pcmcia_resource.c

@@ -256,6 +256,7 @@ int pcmcia_modify_configuration(struct pcmcia_device *p_dev,
 {
 	struct pcmcia_socket *s;
 	config_t *c;
+	int ret;
 
 	s = p_dev->socket;
 
@@ -264,13 +265,13 @@ int pcmcia_modify_configuration(struct pcmcia_device *p_dev,
 
 	if (!(s->state & SOCKET_PRESENT)) {
 		dev_dbg(&s->dev, "No card present\n");
-		mutex_unlock(&s->ops_mutex);
-		return -ENODEV;
+		ret = -ENODEV;
+		goto unlock;
 	}
 	if (!(c->state & CONFIG_LOCKED)) {
 		dev_dbg(&s->dev, "Configuration isnt't locked\n");
-		mutex_unlock(&s->ops_mutex);
-		return -EACCES;
+		ret = -EACCES;
+		goto unlock;
 	}
 
 	if (mod->Attributes & CONF_IRQ_CHANGE_VALID) {
@@ -286,7 +287,8 @@ int pcmcia_modify_configuration(struct pcmcia_device *p_dev,
 
 	if (mod->Attributes & CONF_VCC_CHANGE_VALID) {
 		dev_dbg(&s->dev, "changing Vcc is not allowed at this time\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto unlock;
 	}
 
 	/* We only allow changing Vpp1 and Vpp2 to the same value */
@@ -294,21 +296,21 @@ int pcmcia_modify_configuration(struct pcmcia_device *p_dev,
 	    (mod->Attributes & CONF_VPP2_CHANGE_VALID)) {
 		if (mod->Vpp1 != mod->Vpp2) {
 			dev_dbg(&s->dev, "Vpp1 and Vpp2 must be the same\n");
-			mutex_unlock(&s->ops_mutex);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto unlock;
 		}
 		s->socket.Vpp = mod->Vpp1;
 		if (s->ops->set_socket(s, &s->socket)) {
-			mutex_unlock(&s->ops_mutex);
 			dev_printk(KERN_WARNING, &s->dev,
 				   "Unable to set VPP\n");
-			return -EIO;
+			ret = -EIO;
+			goto unlock;
 		}
 	} else if ((mod->Attributes & CONF_VPP1_CHANGE_VALID) ||
 		   (mod->Attributes & CONF_VPP2_CHANGE_VALID)) {
 		dev_dbg(&s->dev, "changing Vcc is not allowed at this time\n");
-		mutex_unlock(&s->ops_mutex);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto unlock;
 	}
 
 	if (mod->Attributes & CONF_IO_CHANGE_WIDTH) {
@@ -332,9 +334,11 @@ int pcmcia_modify_configuration(struct pcmcia_device *p_dev,
 			s->ops->set_io_map(s, &io_on);
 		}
 	}
+	ret = 0;
+unlock:
 	mutex_unlock(&s->ops_mutex);
 
-	return 0;
+	return ret;
 } /* modify_configuration */
 EXPORT_SYMBOL(pcmcia_modify_configuration);