ixgbe: Break recursion in case of removal

When an adapter is removed and registers all read as all one's,
an infinite recursion can happen between ixgbe_clear_vmdq_generic
and ixgbe_clear_rar_generic. Adding a check for removal breaks
this recursion.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --cc drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
Simple merge