powerpc/pci: Drop unnecessary null test

list_for_each_entry binds its first argument to a non-null value, and thus
any null test on the value of that argument is superfluous.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
iterator I;
expression x,E,E1,E2;
statement S,S1,S2;
@@

I(x,...) { <...
- if (x != NULL || ...)
  S
  ...> }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/pci_of_scan.c

@@ -336,7 +336,6 @@ static void __devinit __of_scan_bus(struct device_node *node,
 		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
 		    dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
 			struct device_node *child = pci_device_to_OF_node(dev);
-			if (dev)
 			of_scan_pci_bridge(child, dev);
 		}
 	}