Pull up following revision(s) (requested by msaitoh in ticket #1070):

sys/dev/pci/ixgbe/if_bypass.c: revision 1.6
sys/dev/pci/ixgbe/ixgbe_common.c: revision 1.28
sys/dev/pci/ixgbe/ixgbe.c: revision 1.246

Fix checking return value of atomic_cas_uint().

This change fixes a bug that extra delay() is called only once even if
atomic_cas_uint() isn't failed or delay() isn't called when atomic_cas_uint()
failed.

The reason of this bug was that I simply converted FreeBSD' atomic_cmpset_int()
to atomic_cas_uint(). The return value's semantics is different.

-

Minor change.
  - Print "X550EM X" instead of "X550EM" for Xeon D devices.
  - Fix typo in comment. Same as FreeBSD.

(martin)