wifi: iwlwifi: mvm: Remove unused last_amsdu from reorder buffer

The last_amsdu field is not used and appears to be a leftover
from a previous implementation, remove it.

Signed-off-by: Daniel Gabay <daniel.gabay@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20241008072037.13ba0eeae0fd.I94985512596e5996f5ab199451ce851c59a5a72a@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>