iwlwifi: mvm: validate firmware sync response size

We send some data to the firmware and expect to get it back,
but we shouldn't really trust the firmware on this. Check the
size of all the data we send down to avoid using bad or just
uninitialized data when the firmware doesn't respond right.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201209231352.a5a8173f16c7.I4fa68bb2b1c7dcc52ddd381c4042722d27c4a34d@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>