ide: fix PCI refcounting

The IDE core never marked the PCI IDE devices as being in use after succesfull
driver probe call (the devices were marked in use only while being probed), and
so was susceptible to issues caused by unsolicited PCI hotplug device removal.
So, add pci_dev_get() call to ide_scan_pcidev() and convert this function to
the kernel style, also dropping a bunch of useless curly braces from its caller,
ide_scan_pcibus() and somewhat beautifying printk() call there, while at it...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>