PCI/AER: Rationalize error status register clearing

The AER interfaces to clear error status registers were a confusing mess:

  - pci_cleanup_aer_uncorrect_error_status() cleared non-fatal errors
    from the Uncorrectable Error Status register.

  - pci_aer_clear_fatal_status() cleared fatal errors from the
    Uncorrectable Error Status register.

  - pci_cleanup_aer_error_status_regs() cleared the Root Error Status
    register (for Root Ports), the Uncorrectable Error Status register,
    and the Correctable Error Status register.

Rename them to make them consistent:

  From                                     To
  ---------------------------------------- -------------------------------
  pci_cleanup_aer_uncorrect_error_status() pci_aer_clear_nonfatal_status()
  pci_aer_clear_fatal_status()             pci_aer_clear_fatal_status()
  pci_cleanup_aer_error_status_regs()      pci_aer_clear_status()

Since pci_cleanup_aer_error_status_regs() (renamed to
pci_aer_clear_status()) is only used within drivers/pci/, move the
declaration from <linux/aer.h> to drivers/pci/pci.h.

[bhelgaas: commit log, add renames]
Link: https://lore.kernel.org/r/d1310a75dc3d28f7e8da4e99c45fbd3e60fe238e.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/ntb/hw/idt/ntb_hw_idt.c

@@ -2674,8 +2674,8 @@ static int idt_init_pci(struct idt_ntb_dev *ndev)
 	ret = pci_enable_pcie_error_reporting(pdev);
 	if (ret != 0)
 		dev_warn(&pdev->dev, "PCIe AER capability disabled\n");
-	else /* Cleanup uncorrectable error status before getting to init */
-		pci_cleanup_aer_uncorrect_error_status(pdev);
+	else /* Cleanup nonfatal error status before getting to init */
+		pci_aer_clear_nonfatal_status(pdev);
 
 	/* First enable the PCI device */
 	ret = pcim_enable_device(pdev);