lib/rstp: Use RSTP_OPER_P2P_MAC_STATE_ENABLED instead of 1.

Signed-off by: Daniele Venturino <daniele.venturino@m3s.it>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
lib/rstp: Use ovs_refcount_unref_relaxed.

Access to RSTP and RSTP port objects is protected by a mutex, so the
refcount unref operation can have relaxed memory order semantics (See
commit 24f8381214966e90819bf4a9ecabf076cbfc1b08).

Signed-off by: Daniele Venturino <daniele.venturino@m3s.it>
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
lib/rstp-common: Remove double spaces.

Signed-off by: Daniele Venturino <daniele.venturino@m3s.it>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>