drivers/ide/pci/sc1200.c: fix suspend/resume buglets and warnings

* We shouldn't bother with dev->current_state, the PCI API functions we
  call manage this for us (and do a far better job at it too).

* Remove pci_set_power_state(dev, PCI_D0) call in resume, as
  pci_enable_device() does the same thing.

* Check pci_enable_device() return value.  If it failed, fail
  the entire resume and avoid programming timings into the [potentially
  dead/asleep] chip.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>