staging: mt7621-pci: Add of_node_put() before return

Each iteration of for_each_available_child_of_node puts the previous
node, but in the case of a return from the middle of the loop, there is
no put, thus causing a memory leak. Hence add an of_node_put before the
return in two places.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Link: https://lore.kernel.org/r/20190716055944.3237-1-nishkadg.linux@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/mt7621-pci/pci-mt7621.c

@@ -400,6 +400,7 @@ static int mt7621_pcie_parse_dt(struct mt7621_pcie *pcie)
 
 		err = of_pci_get_devfn(child);
 		if (err < 0) {
+			of_node_put(child);
 			dev_err(dev, "failed to parse devfn: %d\n", err);
 			return err;
 		}
@@ -407,8 +408,10 @@ static int mt7621_pcie_parse_dt(struct mt7621_pcie *pcie)
 		slot = PCI_SLOT(err);
 
 		err = mt7621_pcie_parse_port(pcie, child, slot);
-		if (err)
+		if (err) {
+			of_node_put(child);
 			return err;
+		}
 	}
 
 	return 0;