Revert "e1000e: driver trying to free already-free irq"

This reverts commit 7e54d9d0.

After additional regression testing, several users are experiencing
kernel panics during shutdown on e1000e devices.  Reverting this
change resolves the issue.

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