FT: Fix R0KH-R1KH protocol data length values

FT: Fix R0KH-R1KH protocol data length values

The FT RRB hostapd packets have a length field. For PULL frames, it
counted the bytes starting with nonce and up to the last before pad. For
RESP frames, it counted the bytes starting with nonce and up to the last
before pad except for 2 bytes. For PUSH frames, it counted the bytes
starting with nonce and up to including pad.

As rounding is done with AES encryption, including pad does not make
sense. Not including the last field before pad does not make sense
either. These were broken in the earlier addition of the 2 octet
pairwise field in commit 1b484d60e55a01d02bf01f790a7c6fb9ea606098 ('FT:
Include pairwise cipher suite in PMK-R0 SA and PMK-R1 SA').

AES encryption is not affected, as rounding hides the differences. The
packets data_length field is not used, so the differences have no effect
there.

This patch changes the constants to match the bytes used, thus excluding
the pad. To validate the changes, look at remainder modulo 8 of the sum
of the size constants and the padding sizes.

Signed-off-by: Michael Braun <michael-dev@fami-braun.de>