e1000e: convert to stats64

e1000e: convert to stats64

Based on the patch provided by Flavio Leitner <fleitner@redhat.com>
Provides accurate stats at the time user reads them.

v2: fixed whitespace/merging issues (by Jeff Kirsher)
v3: fixed namespacing issues (by Bruce Allan)

CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Flavio Leitner <fleitner@redhat.com>