Convert printks to use dev_printk().

I converted DBG() to dev_dbg().  This DBG() is from arch/x86/pci/pci.h and
requires source-code modification to enable, so dev_dbg() seems roughly
equivalent.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>