igb: delay VF reset notification until after interrupts are enabed

This update delays the VF reset notification until after interrupts are
enabled.  Otherwise there is a chance of having the VF try to reset itself too
soon and being ignored by the PF as a result.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>