PCI/PM: Simplify pci_pm_suspend_noirq()

PCI/PM: Simplify pci_pm_suspend_noirq()

We always want to save the device state unless the driver has already done
it.  Rearrange the checking in pci_pm_suspend_noirq() to make this more
clear.  No functional change intended.

[bhelgaas: commit log, rewrap comment]
Link: https://lore.kernel.org/r/20220830104913.1620539-1-rajvi.jingar@linux.intel.com
Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>