ppc4xx: Fix msg "initialization as root-complex failed" upon PCIe scan

ppc4xx: Fix msg "initialization as root-complex failed" upon PCIe scan

This message is printed upon PCIe bus scan, not only upon error, but also
if no PCIe device is detected at all. Since this is not an error, let's
remove this message in this case. We already have the message
"link is not up." if there is no PCIe device present.

Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Wolfgang Denk <wd@denx.de>