PCI: revert broken device warning

This reverts c519a5a7dab2d.  That change added a warning about devices that
didn't respond correctly when sizing BARs, which helped diagnose broken
devices.  But the test wasn't specific enough, so it also complained about
working devices with zero-size BARs, e.g.,
https://bugzilla.kernel.org/show_bug.cgi?id=15822

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>