ofproto-dpif: Shortcut common case in rule_check().

ofproto-dpif: Shortcut common case in rule_check().

Typically the datapath will support all available features, so check
that first before attempting to retrieve various values out of a
minimask as the latter doesn't need to be checked if all fields are
supported.

ct_state is an exception, because support for the bits in this field is
not binary; only some bits are defined so far, so they must still be
checked against the current known supported bits.

Suggested-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Jarno Rajahalme <jarno@ovn.org>