802.11 BA sequence number decode is broken

Bug: 10334
Change-Id: If2da1c5ed63d7e2684a107181d56be38ed921106
Reviewed-on: https://code.wireshark.org/review/3519
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
(cherry picked from commit 3035e6ec92b597169362387d7b8ca1efc3d8064c)
Reviewed-on: https://code.wireshark.org/review/3520