ixgbevf: delete unneeded call to pci_set_power_state

This driver does not need to adjust the power state on suspend, so the
call to pci_set_power_state in the resume function is a no-op.  Drop it,
to make the code more understandable.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>