simplify pnp_activate_dev() and pnp_disable_dev() return values

Make pnp_activate_dev() and pnp_disable_dev() return only 0 (success) or a
negative error value, as pci_enable_device() and pci_disable_device() do.

Previously they returned:

    0:	device was already active (or disabled)
    1:	we just activated (or disabled) device
    <0:	-EBUSY or error from pnp_start_dev() (or pnp_stop_dev())

Now we return only 0 (device is active or disabled) or <0 (error).

All in-tree callers either ignore the return values or check only for
errors (negative values).
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Adam Belay <ambx1@neo.rr.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/pnp/manager.c

@@ -513,7 +513,7 @@ int pnp_activate_dev(struct pnp_dev *dev)
 	int error;
 
 	if (dev->active)
-		return 0;	/* the device is already active */
+		return 0;
 
 	/* ensure resources are allocated */
 	if (pnp_auto_config_dev(dev))
@@ -524,7 +524,7 @@ int pnp_activate_dev(struct pnp_dev *dev)
 		return error;
 
 	dev->active = 1;
-	return 1;
+	return 0;
 }
 
 /**
@@ -538,7 +538,7 @@ int pnp_disable_dev(struct pnp_dev *dev)
 	int error;
 
 	if (!dev->active)
-		return 0;	/* the device is already disabled */
+		return 0;
 
 	error = pnp_stop_dev(dev);
 	if (error)
@@ -551,7 +551,7 @@ int pnp_disable_dev(struct pnp_dev *dev)
 	pnp_clean_resource_table(&dev->res);
 	up(&pnp_res_mutex);
 
-	return 1;
+	return 0;
 }
 
 /**