netxen_nic: Drop 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, so the
driver doesn't need to do it itself.

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 only controls ERR_* Messages from the device.  An ERR_*
Message may cause the Root Port to generate an interrupt, depending on the
AER Root Error Command register managed by the AER service driver.

Also note that the driver only called these for NX_IS_REVISION_P3 devices,
so since f26e58bf, error reporting has been enabled for devices other
than NX_IS_REVISION_P3.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Manish Chopra <manishc@marvell.com>
Cc: Rahul Verma <rahulv@marvell.com>
Cc: GR-Linux-NIC-Dev@marvell.com
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>