sfc: Remove unnecessary use of atomic_t

We can set, get and compare-and-exchange without using atomic_t.
Change efx_mcdi_iface::state to the enum type we really wanted it to
be.

Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2 files changed