pci/hotplug/pnv-php: Remove erroneous warning

On powernv, when removing a device through hotplug, the following
warning is logged:

     Invalid refcount <.> on <...>

It may be incorrect, the refcount may be set to a higher value than 1
and be valid. of_detach_node() can drop more than one reference. As it
doesn't seem trivial to assert the correct value, let's remove the
warning.
Reviewed-by: Alastair D'Silva <alastair@d-silva.org>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191121134918.7155-7-fbarrat@linux.ibm.com

drivers/pci/hotplug/pnv_php.c

@@ -151,17 +151,11 @@ static void pnv_php_rmv_pdns(struct device_node *dn)
 static void pnv_php_detach_device_nodes(struct device_node *parent)
 {
 	struct device_node *dn;
-	int refcount;
 
 	for_each_child_of_node(parent, dn) {
 		pnv_php_detach_device_nodes(dn);
 
 		of_node_put(dn);
-		refcount = kref_read(&dn->kobj.kref);
-		if (refcount != 1)
-			pr_warn("Invalid refcount %d on <%pOF>\n",
-				refcount, dn);
-
 		of_detach_node(dn);
 	}
 }