e1000: checkpatch clean

Redefine DPRINTK macro using do while(0)
__FUNCTION__ to __func__
structs {} on separate lines
Surround negative constants with ()

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>