ixgbe: Remove redundant pci_enable_pcie_error_reporting()

pci_enable_pcie_error_reporting() enables the device to send ERR_*
Messages.  Since f26e58bf ("PCI/AER: Enable error reporting when AER is
native"), the PCI core does this for all devices during enumeration.

Remove the redundant pci_enable_pcie_error_reporting() call from the
driver.  Also remove the corresponding pci_disable_pcie_error_reporting()
from the driver .remove() path.

Note that this doesn't control interrupt generation by the Root Port; that
is controlled by the AER Root Error Command register, which is managed by
the AER service driver.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Tony Nguyen <anthony.l.nguyen@intel.com>
Cc: intel-wired-lan@lists.osuosl.org
Cc: netdev@vger.kernel.org
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>